Software Engineer — Reverse Engineering & Legacy Integrations — Careers

About Psyrin

Psyrin builds AI for behavioral health. Our voice agent, Mira, runs the clinical interviews around a behavioral health visit: intake, consent, screening, and a structured psychiatric pre-assessment. It then drafts the assessment and treatment plan documentation for the clinician to review and sign.

Across our partner clinics, Mira has given clinicians 3.3× the assessment capacity per hour of manual assessment (as of September 2026). Psyrin is live with multiple behavioral health organizations, most of them community mental health and addiction providers, as well as work with state government. Our work serves Medicare and Medicaid patients, some of the most vulnerable populations in America.

The company was founded by doctors, psychologists, and AI researchers, largely from King's College London. We're published in Nature and backed by top thesis-driven investors.

While others build surface-level apps, we dig deep into the root causes of psychiatry's problems: inconsistent assessment quality, subjective diagnoses, and fragmented measurement systems. By capturing not just what patients say but how they say it, we're working toward our long-term vision: democratizing access to psychiatric evaluation and building precision psychiatry with AI. In short, an AI psychiatrist, built with the scientific rigor that mental healthcare demands.

The role

We're building an AI platform for mental healthcare, and we're looking for an exceptional engineer with experience reverse-engineering undocumented APIs and building connectors between legacy enterprise systems and modern applications.

We want someone who loves figuring out how complex software works from the outside, can reverse-engineer black-box behaviour, and turn their discoveries into reliable, production-grade integrations.

The challenge

We integrate with legacy Electronic Health Record (EHR) platforms, many built over 20 years ago on Oracle/PL-SQL, Microsoft SQL Server, and other legacy enterprise backends.

Behind these internal application APIs are complicated stored procedures, hidden server-side session state, inconsistent validation, and limited transactional guarantees.

We build Chrome browser extensions that use an authenticated user's session to interact with the same APIs used by the official EHR web application. A seemingly simple operation, such as creating a patient or saving a clinical note, can involve 10 or more dependent API calls.

The hardest part is not making the happy path work (although that isn't always easy). It's anticipating everything that could go wrong.

Without documentation or vendor support, you'll be responsible for proactively identifying and mitigating failure scenarios across long, stateful chains of operations: partial writes, unexpected server state, concurrency, duplicate records, interrupted requests, and subtle data-integrity issues. You'll need to reason about what the system might be doing internally, test your hypotheses, and design integrations that fail safely when assumptions don't hold.

What we're looking for

Real experience reverse-engineering software interfaces and building working integrations against undocumented APIs is our strongest requirement.

We're particularly interested in engineers who have built connectors into legacy systems by investigating how their existing applications communicate with their backends, rather than consuming officially supported, documented APIs.

Relevant experience might include:

Online travel booking: Automating booking portals, travel-agent applications, or complex GDS workflows, particularly through reverse-engineered APIs, browser extensions, or browser-based automation.
Payroll and HR connectivity: Building integrations into payroll providers or workforce platforms through undocumented web interfaces.
Insurance: Automating legacy carrier portals, quoting systems, policy administration, or claims workflows.
Banking and financial connectivity: Reverse-engineering online banking interfaces, account aggregation, or complex financial transaction workflows.
Other legacy enterprise software: Building unsupported connectors, automation, or interoperability layers for complex, stateful applications.

The scale or commercial success of the project matters far less than what you personally figured out and built. Relevant experience could come from a substantial hobby project, an independent experiment, a one-person commercial product, or an engineering team.

You'll also need:

Strong JavaScript/TypeScript, HTTP, browser, and modern web application fundamentals.
Experience or strong familiarity with Chrome extensions, browser APIs, and session management.
Exceptional analytical reasoning, resourcefulness, and an ability to infer complex system behaviour from limited evidence.
Deep attention to correctness, concurrency, partial failures, and data integrity.
The ability to produce maintainable software while moving exceptionally quickly.
Proactivity and agency.
To be comfortable and happy with full ownership over integration.
Strong passion towards mental health and the company's mission.
Strategic planning around design and ability (or strong willingness) to anticipate diverse user behaviors.
Almost obsessive enthusiasm and interest in your field of work with the strong, continuous desire to improve.
To be comfortable with an early stage, high-velocity, quickly changing start up environment and work independently with minimal managerial oversight.
To have the ability to reflect, admit your mistakes, own them, learn from them and bounce back stronger.
To care - about your work, impact and colleagues.
Willingness to learn HIPAA requirements and handle protected health information carefully.
Able to travel to the US for business when needed.

How we work

We are a high-velocity engineering team. Our ambition is to build, in months, integrations that would traditionally take years to deliver in healthcare.

We're looking for someone who combines deep technical curiosity with urgency and execution. Someone equally comfortable with modern application architecture and the messy realities of legacy enterprise systems, who challenges assumptions, experiments rapidly, and finds creative ways around difficult technical constraints without compromising correctness.

We expect you to be highly proficient with modern AI-assisted engineering tools, using them to accelerate research, reverse engineering, implementation, testing, and iteration while independently validating their outputs.

We believe software engineering is changing fundamentally. We want someone who recognises that change, embraces emerging tools and techniques, and wants to help define what highly effective software engineering looks like over the next few years.

We care about exceptional ability, demonstrated ingenuity, agency and what you can actually build - not job titles, credentials, or years of experience.

Location and travel

Based in the San Francisco Bay Area or London. We'll also consider candidates elsewhere in the UK or US who can travel to San Francisco or London regularly.
We meet in person for a team retreat once a quarter.
You must already have the right to work in the UK or the US, and be able to travel to the US for business when needed.

Compensation and benefits

A competitive base salary, depending on experience and location.
An equity grant.
Benefits: unlimited PTO and quarterly in-person team retreats for everyone; in the US, 100% of premiums paid for PPO Platinum (or equivalent) health insurance plus dental and vision, a safe harbor 401(k) with a 3–5% employer match, one round-trip flight home a year, and Groundfloor membership for Bay Area staff; in the UK, a Revolut Ultra subscription and a NEST workplace pension. Full details on our careers page.
All work travel costs covered.

How to apply

Send your CV to careers@psyrin.ai with a short note on why you want to build in psychiatry and behavioral health, and how Psyrin's mission fits with yours.

Psyrin is an equal opportunity employer. We welcome applicants of every background and don't discriminate on the basis of race, religion, color, national origin, sex, sexual orientation, gender identity, age, disability, veteran status, or any other protected characteristic.