Senior Backend Software Engineer Application Development Jobs

Who we are About Stripe Stripe, LLC. is a financial infrastructure platform for businesses. Millions of companies - from the world’s largest enterprises to the most ambitious startups - use Stripe to accept payments, grow their revenue, and accelerate new business opportunities. Our mission is to increase the GDP of the internet, and we have a staggering amount of work ahead. That means you have an unprecedented opportunity to put the global economy within everyone's reach while doing the most important work of your career. What you’ll do Responsibilities Building and operating critical, large-scale systems that manage massive volumes of financial information, to fulfill business goals for Stripe and its partners; Navigate a complex fintech environment with numerous compliance regulations, translating internal and external business needs into robust software requirements and scalable distributed systems; Lead cross- functional alignment and provide technical direction for multi-team projects; Build large-scale (petabyte-size) financial data platforms, solutions, and pipelines using Big Data technologies and distributed systems; Debugging production issues across the stack, analyzing complex datasets and designing large-scale data pipelines using modern Big Data technologies to ensure reliable, high-performance solutions; Executing projects related to insights into Stripe’s financial performance across multiple Stripe products; Work on systems critical to Stripe's future financial operations, with impact over billions of dollars of payment volume; Deeply understand the design and architecture of modern payments and financial technology across countries; and Leverage experience with monitoring, incident handling, debugging in production environments to ensure data pipeline health and SLOs, while reducing operational toil via automation. Who you are Minimum requirements Must have a Bachelor's Degree or foreign equivalent degree in Computer Science, Information Systems

At Affirm, we exist for the moments that matter—giving people a clear, predictable way to pay over time, with no hidden fees, no surprises, and no tradeoffs on what matters most. The Consumer Authentication Platform team is looking for a passionate Senior Software Engineer to help build the secure, reliable, and seamless authentication experiences that connect millions of consumers with Affirm’s financial products. Authentication is the front door to Affirm. Our systems power critical consumer journeys (including sign-up, sign-in, account recovery, checkout authentication, step-up challenges, session management, and connected merchant experiences) across thousands of merchants and multiple countries. We build foundational capabilities such as authentication factors, identity federation, session and authorization services, and risk-based authentication that protect consumers while minimizing unnecessary friction. We work closely with Product, Security, Fraud, Identity, Analytics, Compliance, Data Science, and a wide range of engineering teams to both leverage existing systems and build new systems. This role requires a high level of technical capability, strong cross-functional communication, and a creative mindset. Our work needs to be secure, reliable, correct, scalable, and extensible. Our job is to build an authentication platform that balances security, regulatory requirements, fraud prevention, customer experience, and business growth. As a senior engineer, you will lead significant technical initiatives, influence the architecture and evolution of the platform, and help the team deliver secure authentication capabilities that can be reused across products, merchants, and geographies. What You’ll Do You will own the technical design and delivery of significant authentication platform capabilities, leading projects from early requirements and architecture through implementation, rollout, and ongoing operation. You will build secure, highly available systems that

At Affirm, we exist for the moments that matter—giving people a clear, predictable way to pay over time, with no hidden fees, no surprises, and no tradeoffs on what matters most. Affirm’s Identity team is mission-critical to the customer checkout experience. When a customer chooses Affirm, one of the first steps is an identity check, and our ability to make the right decision directly impacts conversion, revenue, fraud exposure, and regulatory compliance. Our team owns Identity for all markets outside North America, playing a key role in Affirm’s international expansion. We are responsible for KYC, user lifecycle management, and identity decisioning across multiple regulatory environments. This work is about shaping how Affirm adapts its core Identity platform to new market dynamics, customer expectations, and compliance requirements. We are a team of six engineers based across Spain and Poland. We are looking for a Senior Software Engineer who can turn ambiguous business and customer problems into reliable, well-designed technical solutions. In this role, you will help shape our quarterly technical direction, translate team goals into concrete projects, and identify cross-cutting risks, tradeoffs, and opportunities. You should be comfortable designing across system boundaries, driving collaboration with partner teams, and advocating for technical investments that improve long-term execution. We’re looking for someone who takes ownership beyond shipping code: raising code quality and review standards, making performance, availability, and scale tradeoffs explicit, and improving the operational health of the systems they own. You’ll help reduce toil, create useful playbooks, mentor engineers, support new hires and interns, and contribute to high-signal hiring. Most importantly, we’re excited to work with someone who leaves things better than they found them, communicates clearly across audiences, uses customer feedback to influence technical plans, and help

Why join us Brex is the intelligent finance platform that enables companies to spend smarter and move faster in more than 200 markets. By combining global corporate cards and banking with intuitive spend management, bill pay, and travel software, Brex enables founders and finance teams to accelerate operations, gain real-time visibility, and control spend effortlessly. Brex’s AI-native automation and world-class service eliminate manual expense and accounting tasks for customers so they can focus on what matters most. Tens of thousands of the world's best companies run on Brex, including DoorDash, Coinbase, Robinhood, Zoom, Plaid, Reddit, and SeatGeek. Working at Brex allows you to push your limits, challenge the status quo, and collaborate with some of the brightest minds in the industry. We’re committed to building a diverse team and inclusive culture and believe your potential should only be limited by how big you can dream. We make this a reality by empowering you with the tools, resources, and support you need to grow your career. Engineering at Brex Engineering at Brex is about building systems that scale with speed and intention. Our teams span Software, Data, Security, and IT, and operate with high autonomy and deep collaboration. We tackle hard technical problems, own our outcomes, and push for excellence at every level — from architecture to deployment. It’s an environment where engineering is a craft, and builders become leaders. What you’ll do As an engineer at Brex, you will help develop new products from concept to launch, whether for a 5-person startup or a 5,000-person-strong enterprise. We’re looking for folks with an interest in building products and tools, and who are comfortable in dealing with lots of moving pieces. You’ll be building customer-facing products that will drive direct business impact and shape our long-term technical vision with a high-quality bar. You'll have the opportunity to learn and push the frontier of providing the best fin

Why join us Brex is the intelligent finance platform that enables companies to spend smarter and move faster in more than 200 markets. By combining global corporate cards and banking with intuitive spend management, bill pay, and travel software, Brex enables founders and finance teams to accelerate operations, gain real-time visibility, and control spend effortlessly. Brex’s AI-native automation and world-class service eliminate manual expense and accounting tasks for customers so they can focus on what matters most. Tens of thousands of the world's best companies run on Brex, including DoorDash, Coinbase, Robinhood, Zoom, Plaid, Reddit, and SeatGeek. Working at Brex allows you to push your limits, challenge the status quo, and collaborate with some of the brightest minds in the industry. We’re committed to building a diverse team and inclusive culture and believe your potential should only be limited by how big you can dream. We make this a reality by empowering you with the tools, resources, and support you need to grow your career. Engineering at Brex Engineering at Brex is about building systems that scale with speed and intention. Our teams span Software, Data, Security, and IT, and operate with high autonomy and deep collaboration. We tackle hard technical problems, own our outcomes, and push for excellence at every level — from architecture to deployment. It’s an environment where engineering is a craft, and builders become leaders. What you’ll do As an engineer at Brex, you will help develop new products from concept to launch, whether for a 5-person startup or a 5,000-person-strong enterprise. We’re looking for folks with an interest in building products and tools, and who are comfortable in dealing with lots of moving pieces. You’ll be building customer-facing products that will drive direct business impact and shape our long-term technical vision with a high-quality bar. You'll have the opportunity to learn and push the frontier of providing the best fin

Why join us Brex is the intelligent finance platform that enables companies to spend smarter and move faster in more than 200 markets. By combining global corporate cards and banking with intuitive spend management, bill pay, and travel software, Brex enables founders and finance teams to accelerate operations, gain real-time visibility, and control spend effortlessly. Brex’s AI-native automation and world-class service eliminate manual expense and accounting tasks for customers so they can focus on what matters most. Tens of thousands of the world's best companies run on Brex, including DoorDash, Coinbase, Robinhood, Zoom, Plaid, Reddit, and SeatGeek. Working at Brex allows you to push your limits, challenge the status quo, and collaborate with some of the brightest minds in the industry. We’re committed to building a diverse team and inclusive culture and believe your potential should only be limited by how big you can dream. We make this a reality by empowering you with the tools, resources, and support you need to grow your career. Engineering at Brex Engineering at Brex is about building systems that scale with speed and intention. Our teams span Software, Data, Security, and IT, and operate with high autonomy and deep collaboration. We tackle hard technical problems, own our outcomes, and push for excellence at every level — from architecture to deployment. It’s an environment where engineering is a craft, and builders become leaders. What you’ll do As an engineer at Brex, you will help develop new products from concept to launch, whether for a 5-person startup or a 5,000-person-strong enterprise. We’re looking for folks with an interest in building products and tools, and who are comfortable in dealing with lots of moving pieces. You’ll be building customer-facing products that will drive direct business impact and shape our long-term technical vision with a high-quality bar. You'll have the opportunity to learn and push the frontier of providing the best fin

Why join us Brex is the intelligent finance platform that enables companies to spend smarter and move faster in more than 200 markets. By combining global corporate cards and banking with intuitive spend management, bill pay, and travel software, Brex enables founders and finance teams to accelerate operations, gain real-time visibility, and control spend effortlessly. Brex’s AI-native automation and world-class service eliminate manual expense and accounting tasks for customers so they can focus on what matters most. Tens of thousands of the world's best companies run on Brex, including DoorDash, Coinbase, Robinhood, Zoom, Plaid, Reddit, and SeatGeek. Working at Brex allows you to push your limits, challenge the status quo, and collaborate with some of the brightest minds in the industry. We’re committed to building a diverse team and inclusive culture and believe your potential should only be limited by how big you can dream. We make this a reality by empowering you with the tools, resources, and support you need to grow your career. Engineering at Brex Engineering at Brex is about building systems that scale with speed and intention. Our teams span Software, Data, Security, and IT, and operate with high autonomy and deep collaboration. We tackle hard technical problems, own our outcomes, and push for excellence at every level — from architecture to deployment. It’s an environment where engineering is a craft, and builders become leaders. What you’ll do As an engineer at Brex, you will help develop new products from concept to launch, whether for a 5-person startup or a 5,000-person-strong enterprise. We’re looking for folks with an interest in building products and tools, and who are comfortable in dealing with lots of moving pieces. You’ll be building customer-facing products that will drive direct business impact and shape our long-term technical vision with a high-quality bar. You'll have the opportunity to learn and push the frontier of providing the best fin

About Appier Appier (TSE: 4180) is an AI-native Agentic AI as a Service (AaaS) company that empowers businesses to create value through cutting-edge AdTech and MarTech solutions. Founded in 2012 with the vision of “Making AI Easy by Making Software Intelligent,” Appier helps businesses turn AI into ROI through its Ad Cloud, Personalization Cloud, and Data Cloud—each powered by Agentic AI that enables autonomous, adaptive, and real-time decision-making. Today, Appier operates 17 offices across APAC, the US, and EMEA, and is listed on the Tokyo Stock Exchange. Learn more at www.appier.com. About Ad Cloud Serving Services Team At Appier's Ad Cloud Team Serving Services Team, we build and maintain the critical systems that power the core of Appier's advertising technology. These systems handle massive, high-concurrency, real-time requests, and ensure the stability, low latency, and high performance of our ad delivery. Our SRE professionals are crucial in guaranteeing these services remain reliable under extreme loads, continuously enhancing product availability and performance through innovation and automation . Responsibilities Lead the design and development of scalable, high-performance, and reliable backend services for real-time ad recommendation, data serving, and core ad tech infrastructure. Drive technical roadmap and ownership for sizable projects, ensuring the delivery of robust and efficient solutions within the Ad Cloud ecosystem. Optimize critical system components for latency, throughput, and resource utilization, including database interactions (e.g., MongoDB sharding, ClickHouse optimizations) and network architecture. Enhance system observability, incident management, and operational excellence by implementing comprehensive monitoring, alerting (e.g., Grafana, Prometheus), and refining production SOPs. Collaborate closely with product managers and scientists to translate business requirements into technical designs and ensure seamless integr

At Affirm, we exist for the moments that matter—giving people a clear, predictable way to pay over time, with no hidden fees, no surprises, and no tradeoffs on what matters most. The Growth Platform Engineering team builds the core systems and tools that drive user acquisition, engagement, and lifecycle growth at Affirm. Our platform enables personalized communications, intelligent experimentation, and scalable services that help customers discover and adopt Affirm’s products. We collaborate closely with Product, Data Science, and Experience teams to design APIs, event-driven services, and experimentation frameworks that reach millions of customers across thousands of merchants. This team’s work directly impacts how customers experience Affirm and fuels our long-term growth. We’re looking for a passionate Senior Software Engineer to design and build backend systems that power Affirm’s growth engine. This is a high-impact, cross-functional role that combines technical excellence with strong product intuition. You’ll contribute to scalable, secure, and extensible services that enable Affirm to reach new customers, improve engagement, and expand our product ecosystem. The systems you build will directly influence customer experiences and Affirm’s overall growth trajectory. What you'll do Drive planning and prioritization of projects based on product, technical, and business goals using data-driven decision making. Design and build scalable backend systems, APIs, and data models that power communications, experimentation, and personalization. Partner with Product Managers, Data Scientists, and Analysts to define and execute strategies for customer acquisition and engagement. Establish and uphold engineering best practices to ensure services are secure, observable, and performant at scale. Mentor and support junior engineers, contributing to a culture of learning, collaboration, and technical excellence. What we look for 6+ years of experience as a Software Engineer with

At Affirm, we exist for the moments that matter—giving people a clear, predictable way to pay over time, with no hidden fees, no surprises, and no tradeoffs on what matters most. The Engineering team builds systems that power Affirm’s mission. We take pride in our craft, building reliable, performant, and scalable solutions that touch every part of the business. Whether we’re enabling new ways to pay, ensuring our platforms can scale to the most demanding levels in the industry, or developing seamless servicing experiences, our focus is on solving complex problems through exceptional engineering. About the role As a Senior Software Engineer on Loan Origination and Reporting, you’ll build and scale the data platforms and services that process loan originations in real time and deliver accurate reporting to Affirm and its financial partners, strengthening the core financial engine behind transparent, reliable ways to pay over time. What you’ll do You will be responsible for owning and delivering quarterly goals for your team, leading engineers on your team through ambiguity to solve open-ended problems, and ensuring that everyone is supported throughout delivery. You will support your peers and stakeholders in the product development lifecycle by collaborating with product management, design & analytics by participating in ideation, articulating technical constraints, and partnering on decisions that properly consider risks and trade-offs. You will proactively identify project, process, technology or business issues, advocate for them, and lead in solving them. You will support the operations and availability of your team’s artifacts by creating and monitoring metrics, escalating when needed, and supporting “keep the lights on” & on-call efforts. You will foster a culture of quality and ownership on your team by setting or improving code review and design standards for your team, and advocating for them beyond your team through your writing and tech talks. You

At Affirm, we exist for the moments that matter—giving people a clear, predictable way to pay over time, with no hidden fees, no surprises, and no tradeoffs on what matters most. The Partner Merchant Interfaces - Integration team within Decisions Foundations is growing and we are looking for a Software Engineer. You will be part of a fast paced team which is responsible for the APIs that Partners and Merchants use to integrate with Affirm, and also power some of our top partners like Amazon and Stripe. What You'll Do · With the support of your team, you will work on tasks that contribute to the team's projects and goals. · You will work collaboratively and proactively with your team and stakeholders, bringing them along for your work and helping to create visibility and dialog regarding the risks and trade-offs related to your work. · You will strike the right balance of speed and quality in your work, ensuring that we hit our business goals while protecting our systems from downtime. · You will contribute to a sense of community on your team by engaging in growth and development activities. What We Look For · You have previous work or internship experience designing, developing and launching backend systems at scale and are experienced using one of Python or Kotlin. · You are familiar with the building blocks of distributed systems, and the technologies like AWS, MySQL and Kubernetes. · You have mastered taking a simple problem or business scenario into a solution that interacts with multiple software components, and executing on it by writing clear, easily understood, well tested and extensible code. · You are comfortable navigating a large code base, debugging others' code, and providing feedback to other engineers through code reviews. · Your experience demonstrates that you take ownership of your growth, proactively seeking feedback from your team, your manager, and your stakeholders. · You have strong verbal and written communication skills that support effect

At Affirm, we exist for the moments that matter—giving people a clear, predictable way to pay over time, with no hidden fees, no surprises, and no tradeoffs on what matters most. The Partner Merchant Interfaces - Integration team within Decisions Foundations is growing and we are looking for a Software Engineer. You will be part of a fast paced team which is responsible for the APIs that Partners and Merchants use to integrate with Affirm, and also power some of our top partners like Amazon and Stripe. What You'll Do · With the support of your team, you will work on tasks that contribute to the team's projects and goals. · You will work collaboratively and proactively with your team and stakeholders, bringing them along for your work and helping to create visibility and dialog regarding the risks and trade-offs related to your work. · You will strike the right balance of speed and quality in your work, ensuring that we hit our business goals while protecting our systems from downtime. · You will contribute to a sense of community on your team by engaging in growth and development activities. What We Look For · You have previous work or internship experience designing, developing and launching backend systems at scale and are experienced using one of Python or Kotlin. · You are familiar with the building blocks of distributed systems, and the technologies like AWS, MySQL and Kubernetes. · You have mastered taking a simple problem or business scenario into a solution that interacts with multiple software components, and executing on it by writing clear, easily understood, well tested and extensible code. · You are comfortable navigating a large code base, debugging others' code, and providing feedback to other engineers through code reviews. · Your experience demonstrates that you take ownership of your growth, proactively seeking feedback from your team, your manager, and your stakeholders. · You have strong verbal and written communication skills that support effect

At Affirm, we exist for the moments that matter—giving people a clear, predictable way to pay over time, with no hidden fees, no surprises, and no tradeoffs on what matters most. The Money Movement & Card Ledger team is looking for a passionate Software Engineer to help build the tools and systems that we use to manage money movement, bank data integration & merchant data. Affirm Card is Affirm’s newest financial product that marries the functionality of a debit card with access to Affirm's buy now pay later financing options. Our ability to move money effectively is critical to our ability to reach new customers and improve financial lives. We work closely with experience, data science, product, and a wide range of engineering teams to both leverage existing systems and build new systems. This role requires a high level of technical capability, strong cross functional communication, and a creative mindset. Our work needs to be correct, scalable, and extensible. Our job is to have an industry leading money movement system to empower our product. Affirm is experiencing explosive growth with millions of customers across thousands of merchants in-store and online, and your contributions will be a key enabler of that growth. Come join us as we build a beloved, lasting financial services brand predicated on honesty and trust. It’s going to be an amazing ride! What you'll do You will be responsible for owning and delivering quarterly goals for your team, leading engineers on your team through ambiguity to solve open-ended problems, and ensuring that everyone is supported throughout delivery. You will support your peers and stakeholders in the product development lifecycle by collaborating with product management, design & analytics by participating in ideation, articulating technical constraints, and partnering on decisions that properly consider risks and trade-offs. You will proactively identify project, process, technology or business issues, advocate for t

At Affirm, we exist for the moments that matter—giving people a clear, predictable way to pay over time, with no hidden fees, no surprises, and no tradeoffs on what matters most. Auth Experience owns the customer journeys during authentication, verification, and fraud journeys. You'll work to build the backend orchestration layers that drive our Web and Mobile surfaces. In this role, you will need to gain a deep understanding of the business, product and engineering context, and utilize that context to own and deliver high-availability and low-latency systems that Affirm customers use every day. What You'll Do · You will be responsible for owning and delivering quarterly goals for your team, leading engineers on your team through ambiguity to solve open-ended problems, and ensuring that everyone is supported throughout delivery. · You will support your peers and stakeholders in the product development lifecycle by collaborating with product management, design & analytics by participating in ideation, articulating technical constraints, and partnering on decisions that properly consider risks and trade-offs. · You will proactively identify project, process, technology or business issues, advocate for them, and lead in solving them. · You will support the operations and availability of your team’s artifacts by creating and monitoring metrics, escalating when needed, and supporting “keep the lights on” & on-call efforts. · You will foster a culture of quality and ownership on your team by setting or improving code review and design standards for your team, and advocating for them beyond your team through your writing and tech talks. · You will help develop talent on your team by providing feedback and guidance, and leading by example. What We Look For · You have 4+ years of experience designing, developing and launching backend systems at scale using languages like Python or Kotlin. · You have a track record of developing highly available distributed systems us

At Affirm, we exist for the moments that matter—giving people a clear, predictable way to pay over time, with no hidden fees, no surprises, and no tradeoffs on what matters most. The vision for the Batch Infra team @ Affirm team is to provide reliable, scalable, self-serve and Affirm-optimized compute solution to enable ML, Product, and Financial Engineering success. Our team is responsible for building and maintaining compute platform that serves as a backbone for processing various Business critical batch workloads at Affirm through a wide suite of scheduled and on-demand compute solutions built on the cloud. Affirm is growing rapidly and so is the need for reliable and high availability frameworks. If solving infrastructure challenges at scale excites you, come join us! What you’ll do You will be responsible for owning and delivering quarterly goals for your team, leading engineers on your team through ambiguity to solve open-ended problems, and ensuring that everyone is supported throughout delivery. You will support your peers and stakeholders in the product development lifecycle by collaborating with product management, design & analytics by participating in ideation, articulating technical constraints, and partnering on decisions that properly consider risks and trade-offs. You will proactively identify project, process, technology or business issues, advocate for them, and lead in solving them. You will support the operations and availability of your team’s artifacts by creating and monitoring metrics, escalating when needed, and supporting “keep the lights on” & on-call efforts. You will foster a culture of quality and ownership on your team by setting or improving code review and design standards for your team, and advocating for them beyond your team through your writing and tech talks. You will help develop talent on your team by providing feedback and guidance, and leading by example. What We Look For: You have 4+ years of experience desig