Applicants must be authorized to work for any employer in the country in which the role is being hired. We are unable to sponsor or take over sponsorship of an employment visa at this time.

Mark43 empowers communities and their governments with technology that improves safety and quality of life. We build modern, resilient software that first responders and public safety agencies depend on in their most critical moments.

We are looking for a Software Engineer to join the Universal Search team at Mark43. Universal Search is our federated search platform. When an officer or dispatcher runs a person, vehicle or property query, it sends that query to authoritative external systems: national and state criminal justice networks, the UK Police National Computer (PNC), driver and vehicle licensing agencies, and commercial data providers. It then normalises the responses and streams the results back in real time into our CAD, RMS and mobile products. You’ll build and improve the integrations, services and real-time features behind it, working on systems that support life-saving decisions for public safety users.

Applicants must be authorized to work for any employer in the country in which the role is being hired. We are unable to sponsor or take over sponsorship of an employment visa at this time.

What You’ll Do

If you were on our team last week, you might have:
Built part of a new external provider integration, such as a UK PNC connection or a commercial person-search API. That covered request mapping, authentication, and handling partial or error responses, working from a design doc you helped refine.
Mapped and normalised a new source’s response format into our standard result model, so that persons, vehicles and cautions display correctly in CAD and RMS.
Worked on our real-time query pipeline, including Kafka event streams, Lambda functions and the WebSocket layer that streams results to users. For example, you fixed a bug where partial results or read status weren’t reaching the client.
Extended our configuration-driven platform, adding a per-department configuration or rule handler so a new agency could be onboarded without custom code.
Used AI-assisted coding and review tools (we use Claude Code) to move faster, while keeping code well-tested and easy to maintain.
Reviewed teammates’ pull requests across the Java services and React micro-frontend, giving thoughtful feedback on correctness, resilience and readability.
Helped prepare and verify a release across services, checking feature flags, testing in staging and monitoring after deployment.
Improved observability by adding Datadog metrics, propagating correlation IDs across service calls, and making sure no PII leaks into logs.
Took part in the on-call rotation, investigated a spike in failed provider queries, and contributed to the Root Cause Analysis (RCA) and follow-up fixes.

What You’ll Need

We’re looking for a backend-focused engineer with 3+ years of professional experience. You should be able to take ownership of well-scoped features, work with autonomy, and grow your skills in a distributed, integration-heavy environment.

Must-Haves:

Proficiency in modern Java (17+, ideally 21) and Spring Boot, with a track record of writing well-tested, maintainable production code.
Experience integrating with third-party systems and APIs (REST, and ideally SOAP/XML), including handling errors, timeouts and inconsistent data.
Familiarity with event-driven systems using Kafka, such as producers and consumers, consumer groups, idempotency and retries.
Familiarity with real-time communication using WebSockets, such as connection lifecycle and pushing live updates to clients.
Hands-on experience with AWS services such as Lambda, S3, DynamoDB, Secrets Manager, IAM and CloudWatch, plus relational databases (MySQL) and caching (Redis).
An understanding of data mapping and transformation between different schemas.
Comfort working with CI/CD, containers and integration testing (e.g. Testcontainers, LocalStack).
Practical experience using AI-assisted development tools to deliver faster without compromising quality.