Senior Software Engineer - Universal Search

Mark43’s mission is to empower communities and their governments with new technologies that improve safety and quality of life for all. We build powerful, scalable, and elegant software that sets a new standard for the tools on which first responders rely. Our users are diverse, and we are committed to embracing diversity of thought and experience within our team.

We are looking for an experienced Senior Software Engineer - Universal Search to lead the next phase of our third-party search and data integration platform at Mark43. In this role, you will own some of the most complex and impactful technical initiatives within the Universal Search domain, building and scaling the systems that power fast, accurate, secure access to critical data across our RMS, CAD, and analytics products. You will drive architecture across service boundaries, shape platform direction with cross-functional partners, and raise technical standards for distributed systems, real-time indexing, authorization-aware retrieval, and search reliability in support of life-saving decision-making for public safety users.

What You'll Do

If you were part of our team last week, you might have:

• Led the design of a new external provider integration, such as a UK PNC connection or a commercial person-search API. You worked through authentication, request mapping, partial and error responses, and result normalisation, then wrote it up as a design doc and spec before breaking it into deliverable tasks.

• Evolved our real-time query pipeline: the Lambda functions that route queries, and the WebSocket layer that streams results to users. You improved how query state, read status and partial results reach CAD and RMS clients.

• Extended our configuration-driven platform. That means versioned, per-department configurations, bundles and rule handlers that let us onboard a new agency or state system without one-off code, and promote those configurations safely across environments.

• Reviewed designs and pull requests across the Java services, Lambda functions and React micro-frontend. You gave clear, high-impact feedback on resilience, data handling and contract design.

• Coordinated a release spanning several services and product teams (CAD, RMS, OnScene), managing feature flags, dependencies and rollout to minimise customer impact.

• Improved observability: propagated correlation and trace IDs across service and provider boundaries, added Datadog metrics and alerts, and made sure no PII or criminal justice data leaks into logs.

• Mentored engineers through ambiguous technical decisions and helped the team make effective, safe use of AI-assisted development and review tooling.

• Took part in on-call, diagnosed a spike in failed provider queries, led the Root Cause Analysis (RCA), and drove follow-up improvements to resilience, alerting and runbooks.

What You'll Need

We are looking for a senior engineer with 8+ years of professional software engineering experience. You should be able to lead large, ambiguous initiatives on your own, influence decisions beyond your immediate team, and take strong ownership in a distributed, integration-heavy environment.

Must Haves:

• Strong proficiency in modern Java (17+, ideally 21) and Spring Boot, plus working full-stack skills in React and TypeScript, and a track record of production-ready, well-tested, maintainable code.

• Significant experience integrating with third-party systems over varied protocols and formats, such as REST, SOAP/XML and message queues, including handling unreliable upstreams, partial results and inconsistent data.

• Experience building real-time systems with WebSockets: connection lifecycle and session management, scaling across multiple instances, reconnection and delivery guarantees, and pushing live updates to web and mobile clients.

• Hands-on experience with AWS (Lambda, Secrets Manager, AppConfig, DynamoDB, S3, IAM, CloudWatch), relational databases (MySQL) and caching (Redis).

• Solid understanding of data mapping and normalisation: turning heterogeneous source schemas into a consistent, well-defined contract.

• Experience with resilience patterns such as circuit breakers, retries, timeouts and graceful degradation.

• Comfort delivering through CI/CD, containers and Kubernetes, with integration-first testing (e.g. Testcontainers, LocalStack).

• Strong system design skills: services and APIs built for scale, incremental delivery and a low long-term cost of change.

• A track record of leading multi-engineer projects, spotting dependencies early and delivering in ambiguity.

• Effective use of AI-assisted development (we use Claude Code across development and code review) to deliver faster without lowering standards for quality or security.

• Excellent written and verbal communication, including clear design documents and the ability to influence technical and non-technical stakeholders.

• Proven mentorship and technical leadership; a go-to engineer for complex debugging and design reviews.

Nice to Haves:

• Experience with public safety or criminal justice data systems, such as PNC, NCIC or state message switches, or standards such as NIEM.

• Experience with micro-frontends / Module Federation, or OpenAPI-driven contract and code generation.

• Experience with Terraform or other Infrastructure-as-Code, and with Datadog.

• Knowledge of security best practices for sensitive data: authorisation, auditability, encryption, PII handling and data residency.

• Experience owning platform capabilities used by multiple teams, tenants or jurisdictions.

People Who Thrive in This Role Also Tend to Be:

• Mission-driven: You care deeply about building technology that improves lives and strengthens communities.

• Curious and humble: You seek out different perspectives, ask thoughtful questions, and influence through credibility rather than job title.

• Team-oriented: You collaborate effectively across engineering, product, design, infrastructure, and support to deliver lasting outcomes.

• Growth-minded: You invest in your own development and actively help develop the engineers around you.

• Calm under uncertainty: You can make sound decisions, manage risk, and keep delivery moving even when requirements or circumstances are evolving.

What We Offer

• 28 days holiday plus UK bank holidays

• Private medical, dental, and vision insurance through AXA Health and BUPA, fully paid for you and your dependents

• 18 weeks paid parental leave for primary caregivers plus a ramp-back programme

• Income protection (75% of salary) and death in service cover (4x salary), fully paid

• Pension through Nest with 3% employer contribution

• Gym reimbursement for you and your partner

• Equipment allowance to set up your home office

• AI tooling including Claude Code Enterprise and ChatGPT Enterprise licences provided

• Spring Health membership with therapy sessions and mental wellness tools, fully covered

• Company performance-based bonus

• Paid sabbatical of one month at your five-year anniversary

• Biannual hackathons, learning budget, and a team that genuinely invests in your growth 

What We Value

• Humility. You know the best ideas win, no matter where they come from. You ask questions before making assumptions and you're as happy being wrong as being right, because either way, the team gets to a better answer.

• Inclusivity. You respect expertise in all its forms and actively seek out perspectives different from your own. You make space for others and assume good intent.

• Excellence. You care about quality in your code, your reviews, and how you communicate. You're not satisfied with "it works" when it could be better, and you encourage the same standard in those around you.

• Diligence. You take ownership, mind the details, and understand that the software we build is used in moments that genuinely matter. You don't cut corners when people are depending on the outcome.

Location

This role is based at our Manchester office and follows a hybrid work model with at least three days a week in the office. 

Applicants must be authorised to work in the UK. We are unable to sponsor or take over sponsorship of an employment visa at this time. 

This role may require you to complete Non-Police Personnel Vetting (NPPV) security clearance up to level 3.