Senior Software Engineer, Backend (Online Storage)

Affirm, Inc.; St. Louis (MO); Remote; USD 170,000 - 255,000; Full time

Benefits offered by this job

Health coverage for you and dependents

Monthly tech stipend

Flexible time off

Employee stock purchase plan

Job summary

Affir in the United States is seeking a Senior Software Engineer to architect and scale relational and distributed SQL databases, focusing on MySQL and TiDB. You’ll own the control plane, perform zero-downtime migrations, and own the Kubernetes networking stack to ensure reliable, low-latency connections.

You’ll collaborate with product, design, and analytics, setting quarterly goals and leading engineers through ambiguity while delivering high-impact infrastructure improvements in a

Qualifications

• 5+ years of experience as a software engineer.
• Experience designing, developing and launching backend systems at scale technologies like Python, Kotlin, AWS, MySQL, Terraform and Kubernetes.
• Hands-on experience with large-scale database deployments in a production environment.
• Expertise in distributed databases and database technologies such as MySQL, TiDB, Postgres, Spanner, Vitess, CockroachDB.
• Strong understanding of distributed database architecture, data modeling, and performance tuning (SQL tuning).
• Experience with database benchmarking, load testing, and capacity planning.
• Familiarity with connection poolers and proxies such as ProxySQL, RDS Proxy, PgBouncer, PgDog.
• Built control-plane or automation tooling for databases (provisioning, failover, upgrades, migrations) on Kubernetes.
• Experience with zero-downtime migrations and major version upgrades in production.
• Knowledge of Kubernetes networking, service discovery, TLS, and failover debugging.
• Ability to plan, document, and deliver significant features with simple, extensible designs.
• Strong habits for safe large-scale code changes and toolchains.
• Proven ownership of personal and team growth through feedback.
• Excellent verbal and written communication for global collaboration.
• Bachelor’s degree or equivalent practical experience.

Responsibilities

• Build and operate the control plane for large-scale distributed SQL databases (MySQL, TiDB) and automate provisioning, backups and upgrades.
• Design and execute zero-downtime migrations across multi-tenant clusters with minimal product impact.
• Own the networking stack connecting services to storage on Kubernetes and tune for latency and failover.
• Lead your team to deliver quarterly goals, guiding engineers through ambiguity and providing support.
• Collaborate with product, design and analytics through ideation, constraints, and risk/trade-off decisions.
• Identify and drive solutions to project, process, technology, or business issues.
• Monitor artifacts, escalate when needed, and support on-call efforts to keep systems running.
• Set and promote code reviews and design standards across teams to improve quality.
• Mentor colleagues and contribute to talent development through feedback and example.

Skills

Backend design

Distributed databases

Kubernetes

Python

Kotlin

MySQL

TiDB

PostgreSQL

SQL tuning

Proxy servers

Education

Bachelor’s degree or equivalent experience

Tools

ProxySQL

RDS Proxy

PgBouncer

PgDog

Job description

At Affir, 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 Affir’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 Affirers 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 Affir services. Our platform enables self-service access to OLTP storage systems, including Relational DB(MySQL), KV(DynamoDB), Distributed SQL(TiDB) and 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 talented Senior Software Engineer who can architect, build and scale Relational and Distributed SQL Databases identifying opportunities to improve how we build, productionize, 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

• You will build and operate the control plane for large-scale distributed SQL databases such as MySQL and TiDB, automating provisioning, failover, backups and upgrades end to end.
• You will design and execute reliability-focused schema and data migrations across multi-tenant database clusters, with zero downtime for the products that depend on them.
• You will own the networking stack that connects services to storage on Kubernetes, including connection proxies such as ProxySQL, and tune it for latency, resilience and failover.
• 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 a total of 5+ years of experience as a software engineer.
• You are experienced in designing, developing and launching backend systems at scale technologies like Python, Kotlin, AWS, MySQL, Terraform and Kubernetes.
• You have in-depth, hands‑on experience with large-scale database deployments in a production environment.
• You have expertise in distributed databases and database technologies such as MySQL(Preferred), TiDB(Preferred), Postgres, Spanner, Vitess, CockroachDB etc.
• Solid understanding of distributed database architecture, data modeling, and performance tuning. Particularly, expertise in SQL tuning and performance optimization techniques.
• You have expertise in database benchmarking, load testing, and capacity planning.
• You are familiar with connection poolers and proxies such as ProxySQL, RDS Proxy, Pg Bouncer, PgDog etc.
• You have built control‑plane or automation tooling for databases, such as provisioning, failover, upgrades or schema migrations, ideally on Kubernetes.
• You have executed zero-downtime migrations and major version upgrades on production databases, and have built CLI tooling or runbooks to make those procedures repeatable.
• You understand Kubernetes networking, service discovery and TLS well enough to debug connection and failover problems between services and databases.
• You have experience defining a technical plan for the delivery of a significant feature or system component with an elegant, simple and extensible design. You write high quality code that is easily understood and used by others.
• You are proficient at making significant changes in a large codebase, and have developed a suite of tools and practices that enable you and your team to do so safely.
• 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 effective collaboration with our global engineering team.
• This position requires either equivalent practical experience or a Bachelor’s degree in a related field.

Pay Grade - N

Equity Grade - 9

Employees new to Affir typically come in at the start of the pay range. Affir focuses on providing a simple and transparent pay structure which is based on a variety of factors, including location, experience and job-related skills.

Base pay is part of a total compensation package that may include equity rewards, monthly stipends for health, wellness and tech spending, and benefits (including 100% subsidized medical coverage, dental and vision for you and your dependents.)

USA base pay range (CA, WA, NY, NJ, CT) per year: $195,000 - 255,000

USA base pay range (all other U.S. states) per year: $173,000-233,000

Remote-first with flexibility built in

Affir is proud to be a remote-first company. Most roles can be done from almost anywhere within the country of employment. Some positions may occasionally require in-person work at an Affir office, and a few are office-based due to the nature of the work. All new hires will be invited to attend an in-person onboarding experience.

Benefits Designed For You

Our benefits reflect our commitment to care, transparency, and flexibility. Here are a few highlights:

• Health coverage at no cost: We cover 100% of premiums for employees and their dependents.
• Spending stipends: Monthly stipends support your tech setup, and the ability to choose health and wellness options that are right for you.
• Time off to recharge: Flexible time off and generous holiday calendars help you rest when you need to.
• Own a piece of what you build: Our employee stock purchase plan (ESPP) lets you buy Affir stock at a discount.

We’re committed to providing an inclusive interview process, including accommodations for candidates with disabilities. If you need support, we’re happy to help.

For positions based in San Francisco or Los Angeles: Affir considers qualified applicants with arrest and conviction records, as required by law.