Senior Software Engineer

Description: SPS Commerce is a leading provider of cloud-based supply chain management solutions, serving a global network of retail trading partners. We foster a collaborative and inclusive work environment where innovation and continuous improvement are highly valued. Join SPS Commerce and be part of a dynamic team that's transforming the global retail supply chain! Position Summary: We are searching for a Senior Software Engineer based in Poland to design, build, and maintain high-volume, event-driven back-end services and data pipelines for our Fulfillment platform. In this role, you will lead architectural decisions, optimize relational databases, contribute end-to-end across Python and React/TypeScript, champion AI-first engineering practices, and elevate team standards through mentorship and operational excellence. SPS Commerce Fulfillment is the company's flagship SaaS product. It enables vendors to receive and respond to inbound retailer documents (purchase orders, shipment notices, invoices) quickly and reliably, without building or maintaining their own EDI infrastructure. Fulfillment connects a large trading partner network and processes high volumes of business-critical transactions daily. The Fulfillment UI team owns the web application layer customers interact with directly, along with the back-end services behind it. The system is a mix of mature and modern services — the team actively modernizes the platform while maintaining stability for existing users. It is a strong environment for engineers who enjoy both greenfield work and the challenge of evolving a large-scale production system. Key Responsibilities: Design, build, and own back-end services in Python that power the Fulfillment platform: APIs, document workflows, and data processing pipelines Lead design work on non-trivial features: propose architectures, weigh trade-offs, write and review design documents, and drive decisions to closure with the team Build and evolve event-driven and asynchronous processing (streams, queues, scheduled jobs) supporting EDI document workflows at high volume Contribute across the stack including React/TypeScript front-end work so that features ship end-to-end rather than stopping at a service boundary Model and optimize relational data: schema design, query performance, migrations, and partitioning strategies on large production datasets Improve reliability and observability: participate in on-call and incident response, reduce alert noise, and drive the resolution of recurring production issues Raise the engineering bar through code review, pairing, and mentoring of mid-level engineers Partner with product management, UX, and QA to turn business requirements into maintainable solutions, and with adjacent teams on cross-service dependencies Work AI-first: use AI engineering tools as a default part of the delivery loop, and actively improve how the team applies them like shared tooling, prompts and skills, agentic workflows, and sensible guardrails Required Qualifications: 6+ years of professional software engineering experience, with demonstrable ownership of production systems Deep Python expertise for back-end services like Django/DRF, FastAPI, or equivalent — including API design and testing practices Strong relational database skills: schema design, indexing, query optimization, and migrations (PostgreSQL/Aurora, MySQL, or Oracle) Asynchronous and event-driven experience: message queues or streaming (Kafka, Kinesis, SQS/SNS, RabbitMQ) and background task processing (Celery or similar) Cloud experience, AWS preferred (or Azure/GCP with willingness to work in AWS) Design and technical leadership: has driven a meaningful feature or system from ambiguous requirements through design, delivery, and operation Working experience with React and TypeScript or another modern component framework (Vue, Angular) plus a genuine willingness to work in React Production ownership: on-call participation, debugging live incidents, and improving reliability afterwards Solid engineering hygiene: Git, CI/CD, automated testing, code review Comfortable in an Agile/Scrum team and in a distributed setting across time zones Professional working proficiency in English, written and spoken Fluent, daily hands-on use of AI engineering tools (Claude, GitHub Copilot, Cursor or similar) Preferred Experience: Experience with data/analytics pipelines (CDC, warehouse or lakehouse platforms such as Databricks/Snowflake) Exposure to EDI standards or the supply chain / B2B commerce domain Containerization and orchestration (Docker, Kubernetes) and infrastructure-as-code (Terraform) Observability tooling (Grafana, Prometheus/VictoriaMetrics, Sumo Logic) and pragmatic alerting design Search and caching technologies (OpenSearch/Elasticsearch, Redis/ElastiCache) Experience mentoring engineers formally or acting as a tech lead Building LLM-powered product features, agentic tooling, RAG pipelines, or MCP integrations in production represents a significant differentiator for this role Open-source contributions or side projects demonstrating technical depth Location: This role is in our Warsaw office, Poland and the team is in-office 1 day per week. What We Offer: SPS Commerce is the world’s largest retail network, connecting 120,000+ businesses — real impact at scale Fulfillment is a core product with direct business impact — not a side project or experimental team Modern tech stack (Python, React, TypeScript, AWS) with room to influence architectural decisions AI-forward engineering culture - the team actively uses Claude and Copilot in daily work, with growing opportunities to build AI-powered product features Hybrid work model with office presence in Poland — flexibility plus in-person collaboration Opportunity to work on complex data workflows (EDI, supply chain automation) that most engineers never encounter Collaborative, non-hierarchical engineering culture - all ideas are heard, knowledge-sharing is fast and organic, and bureaucracy is minimal Commitment to our Employees: At SPS we power connections that drive the world of commerce forward, and our success depends on making strong decisions, fostering innovation, delivering unparalleled customer solutions, and driving outstanding business performance. We achieve this by creating an environment where every employee feels a true sense of belonging. We embrace diversity, equity, and inclusion, ensuring everyone feels accepted, valued, and empowered to make a meaningful impact. We are committed to affirmative action and equal opportunity in all aspects of employment. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, or status as a protected veteran.