Python Backend Engineer Jobs

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

About Appier Appier is an AI-native Agentic AI as a Service (AaaS) company that uses artificial intelligence (AI) to power business decision-making. Founded in 2012 with a vision of democratizing AI, Appier’s mission is turning AI into ROI by making software intelligent. Appier now has 17 offices across APAC, Europe and U.S., and is listed on the Tokyo Stock Exchange (Ticker number: 4180). Visit www.appier.com for more information. About the role Appier’s solutions are powered by proprietary deep learning and machine learning technologies to empower every business to use AI to turn data into business insights and decisions. As a Software Engineer, Data Backend, you will be involved in helping to build critical components of this platform. Responsibilities Design, develop, and maintain RESTful APIs using Python. Build and manage robust data warehouses utilizing ClickHouse, Trino/Presto and Pinot. Design and develop data pipelines using Apache Airflow and Apache Spark. Work closely with cross-functional teams to develop automation tools that streamline daily operations. Implement state-of-the-art monitoring and alerting systems to ensure optimal system performance and stability. Address queries from applications in a timely and effective manner, ensuring high client satisfaction. Work on cloud platforms such as AWS and GCP, leveraging their capabilities to optimize data operations. Utilize Kubernetes (k8s) for container orchestration to facilitate efficient deployment and scaling of applications. About you [Minimum qualifications] BS/MS degree in Computer Science 2+ years of experience in building and operating large-scale distributed systems or applications Experience in Kubernetes development, Linux/Unix Experience in managing data lake or data warehouse Expertise in developing data structures, algorithms on top of Big Data platforms Ability to operate effectively and independently in a dynamic, fluid environment Ability to wor

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. Identity at Affirm is mission-critical; it is the very first step of the customer journey and the foundation of global expansion. The International Expansion Unit (IEU) owns Identity for every market outside North America, placing our team at the center of Affirm’s global strategy. We are responsible for ensuring Affirm can enter and scale in new markets while operating compliantly across diverse regulatory environments. Our scope includes building and expanding Identity Data Management, KYC Verification, and Decisioning capabilities, while driving architectural changes that impact Identity services globally. We don’t just execute; we influence the core platform’s evolution to support new risk models and market dynamics. Operating at the intersection of technical depth and regulatory complexity, we directly impact approval rates, conversion, and fraud exposure. By joining this team, you will shape the foundational processes that unlock revenue and build customer trust on a global scale. What You'll Do · You will be responsible for setting technical strategy for your team on a year-long time scale, and help your team tie it together with critical, business-impacting projects. · You will collaborate across teams in the product development lifecycle by collaborating with product management, design & analytics to ensure technical sustainability, risks and trade-offs are well understood and managed. · You will act as a force-multiplier for your team through your definition and advocacy of technical solutions and operational processes. · You take ownership of your team’s operations and availability by ensuring you have the right monitoring, triage rotations, playbooks, polcities, testing and alerting in place to support “keep the lights on” & on-call efforts. · You will foster a culture o

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. Identity at Affirm is mission-critical; it is the very first step of the customer journey and the foundation of global expansion. The International Expansion Unit (IEU) owns Identity for every market outside North America, placing our team at the center of Affirm’s global strategy. We are responsible for ensuring Affirm can enter and scale in new markets while operating compliantly across diverse regulatory environments. Our scope includes building and expanding Identity Data Management, KYC Verification, and Decisioning capabilities, while driving architectural changes that impact Identity services globally. We don’t just execute; we influence the core platform’s evolution to support new risk models and market dynamics. Operating at the intersection of technical depth and regulatory complexity, we directly impact approval rates, conversion, and fraud exposure. By joining this team, you will shape the foundational processes that unlock revenue and build customer trust on a global scale. What You'll Do · You will be responsible for setting technical strategy for your team on a year-long time scale, and help your team tie it together with critical, business-impacting projects. · You will collaborate across teams in the product development lifecycle by collaborating with product management, design & analytics to ensure technical sustainability, risks and trade-offs are well understood and managed. · You will act as a force-multiplier for your team through your definition and advocacy of technical solutions and operational processes. · You take ownership of your team’s operations and availability by ensuring you have the right monitoring, triage rotations, playbooks, polcities, testing and alerting in place to support “keep the lights on” & on-call efforts. · You will foster a culture o

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. Identity at Affirm is mission-critical; it is the very first step of the customer journey and the foundation of global expansion. The International Expansion Unit (IEU) owns Identity for every market outside North America, placing our team at the center of Affirm’s global strategy. We are responsible for ensuring Affirm can enter and scale in new markets while operating compliantly across diverse regulatory environments. Our scope includes building and expanding Identity Data Management, KYC Verification, and Decisioning capabilities, while driving architectural changes that impact Identity services globally. We don’t just execute; we influence the core platform’s evolution to support new risk models and market dynamics. Operating at the intersection of technical depth and regulatory complexity, we directly impact approval rates, conversion, and fraud exposure. By joining this team, you will shape the foundational processes that unlock revenue and build customer trust on a global scale. What You'll Do · You will be responsible for setting technical strategy for your team on a year-long time scale, and help your team tie it together with critical, business-impacting projects. · You will collaborate across teams in the product development lifecycle by collaborating with product management, design & analytics to ensure technical sustainability, risks and trade-offs are well understood and managed. · You will act as a force-multiplier for your team through your definition and advocacy of technical solutions and operational processes. · You take ownership of your team’s operations and availability by ensuring you have the right monitoring, triage rotations, playbooks, polcities, testing and alerting in place to support “keep the lights on” & on-call efforts. · You will foster a culture o

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 Data and Storage Services team is responsible for Affirm's data infrastructure across OLTP and OLAP systems, spanning critical online checkout databases, batch orchestration, streaming infrastructure, event-driven frameworks, BI, analytics tooling, large-scale data platforms, and agentic data tools such as semantic layers and internal platform data applications. Our mission is to provide trustworthy, intuitive, and cost-efficient solutions for Affirmers to secure, store, analyze, and transform data at exceptional scale. The Online Storage team provides a set of managed databases as a platform, used to persist data for all Affirm services. Our platform enables self-service access to OLTP storage systems, including Relational DB(MySQL), DynamoDB, Distributed SQL, Cache(Redis). As a team, we are responsible for various data and access patterns, including but not limited to mission-critical financial transactional data, data science models, and any new persistence use case. These responsibilities require us to learn and gain deep expertise in various database systems. We are looking for a highly skilled and detail-oriented Staff Software Engineer who can drive the technical roadmap for our Databases (Relational and KeyValue) identifying opportunities to improve how we build, productize, operate and improve this mission-critical infrastructure to unlock substantial value within our business. You’ll have the opportunity to directly influence your team’s roadmap in close collaboration with your peers, share your knowledge and expertise with others and learn from some of the best on our shared mission to deliver honest financial products that improve lives. What You'll Do As an integral member of the Online Storage team, You will be responsible for setting technical strategy for 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 Data and Storage Services team is responsible for Affirm's data infrastructure across OLTP and OLAP systems, spanning critical online checkout databases, batch orchestration, streaming infrastructure, event-driven frameworks, BI, analytics tooling, large-scale data platforms, and agentic data tools such as semantic layers and internal platform data applications. Our mission is to provide trustworthy, intuitive, and cost-efficient solutions for Affirmers to secure, store, analyze, and transform data at exceptional scale. The Online Storage team provides a set of managed databases as a platform, used to persist data for all Affirm services. Our platform enables self-service access to OLTP storage systems, including Relational DB(MySQL), DynamoDB, Distributed SQL, Cache(Redis). As a team, we are responsible for various data and access patterns, including but not limited to mission-critical financial transactional data, data science models, and any new persistence use case. These responsibilities require us to learn and gain deep expertise in various database systems. We are looking for a highly skilled and detail-oriented Staff Software Engineer who can drive the technical roadmap for our Databases (Relational and KeyValue) identifying opportunities to improve how we build, productize, operate and improve this mission-critical infrastructure to unlock substantial value within our business. You’ll have the opportunity to directly influence your team’s roadmap in close collaboration with your peers, share your knowledge and expertise with others and learn from some of the best on our shared mission to deliver honest financial products that improve lives. What You'll Do As an integral member of the Online Storage team, You will be responsible for setting technical strategy for you