Senior Software Engineer

Proper AI is an AI-first accounting service built for property managers and real estate operators. By combining automation, technology, and a global team of accounting experts, we deliver faster, more accurate financial operations at scale. We’re a team of builders, problem-solvers, and operators from around the world, working together to modernize one of the most critical functions in real estate. Learn more at Proper.ai We are looking for a Senior Software Engineer with strong backend and systems fundamentals to help own the core of our platform: the services, data models, and automations behind workflow and productivity tooling for B2B accounting operations. This is a depth role, not a breadth role. The work is logic-heavy — multi-service data flows, third-party platform integrations, and document-processing pipelines where correctness matters more than surface area. The engineer will be a technical counterpart to the Tech Lead on architecture, and will take ownership of our AI-backed document processing service. The ideal candidate is language-agnostic in outlook but deep in practice: comfortable moving between Go, Python, and TypeScript, and able to build a real working model of an unfamiliar system before changing it.

Key Responsibilities

• Core Functional Responsibilities

  • Design, build, and maintain backend services across a microservices estate (Go, NestJS/TypeScript, Python).

  • Own the AI-backed document processing and classification service (Python/FastAPI): extraction quality, accuracy measurement, and the pipeline around it.

  • Design and maintain integrations with third-party platforms, including authentication, sync cadence, retries, and recovery.

  • Model data deliberately — schemas, migrations, and invariants that hold as the product changes.

  • Debug across service boundaries: correlate behaviour across multiple systems and databases to find the actual cause.

  • Build observability and provenance into automated flows: actions should be traceable, auditable, and reconstructable after the fact.

  • Design for safe automation: idempotency, pre/postconditions, dry-runs, and guardrails on anything that writes to a customer's system of record.

  • Write clean, tested, maintainable code, and leave the systems better instrumented than found.

  Performance and Metrics Tracking

  • Define and track correctness and reliability measures for owned systems (task success, error and fallback rates, accuracy of automated inference).

  • Build evaluation coverage for AI-backed output: scenario tests, invariant checks, and regression detection when a model or prompt changes.

  • Monitor and improve latency, retries, and failure recovery in automated pipelines.

  Training and Development

  • Mentor mid-level engineers on system design, debugging methodology, and testing discipline.

  • Lead design discussions and code reviews.

  • Document architecture decisions, failure modes, and debugging runbooks.

Required Hard Skills

• Backend engineering depth — production services in Go and/or Python; TypeScript/Node useful. Multi-language comfort matters more than any single stack.
• Data modelling and relational databases — PostgreSQL, schema design, migrations, query performance, and reasoning about data integrity.
• Distributed and cross-service debugging — tracing behaviour across services, queues, and databases to isolate a root cause.
• Third-party integration engineering — external APIs with imperfect contracts: auth expiry, partial failures, retries, idempotency.
• Reliability practice — observability, structured logging, tracing, failure-mode analysis, and recovery design.
• Testing and evaluation — unit and scenario tests, invariant checks, and measuring correctness of non-deterministic (AI-backed) output.
• Cloud and infrastructure — GCP preferred (Cloud Run, Cloud SQL, Pub/Sub); Docker and CI/CD.
• Working with LLM-backed services — using them as components, understanding their failure modes, and validating their output. Prior agent-framework experience is a plus, not a requirement.

Required Soft Skills

• Calibrates depth to stakes. Ships routine, low-risk work quickly; deliberately slows down on core systems, data models, and anything touching money or client data — and can tell the difference without being told.

• Verifies before concluding. Checks the premise of a bug report rather than building on it; can distinguish a real defect from correct behaviour measured the wrong way. Reads the system before changing it. Builds a working model of how something actually behaves, then changes it.

• Owns outcomes, not tickets. Goes past the literal ticket text when the ticket is wrong, incomplete, or describes the wrong problem.

• Strong communicator of design decisions, trade-offs, and risk, to technical and non technical audiences.

• Pragmatic and collaborative — high standards without perfectionism, and works well with Product and Operations.

Nice-to-Have Skills / Experiences

• Experience in both high-growth startups and larger engineering organisations. Accounting, fintech, or other domain where correctness is non-negotiable. Document processing, OCR, or information-extraction pipelines.

• Vector databases / retrieval (e.g. Qdrant) and prompt or model evaluation. Frontend familiarity (Vue or React) — useful for full-feature ownership, not a core requirement.

• B2B SaaS background.

Type of Degree

• Bachelor's or Master's in Computer Science, Software Engineering, or a related field — or equivalent practical experience. Strong CS fundamentals matter; the credential does not.

Years of Experience in Field

• 6+ years of professional software engineering, with a majority in backend or systems work. Demonstrated ownership of a non-trivial production system (not just feature delivery within someone else's design).

• Experience at an organisation with mature engineering standards is valuable.