KAWORKS

We are currently looking for a Senior Full Stack PHP Developer to join a professional German-based product company team that designs innovative eHealth solutions for hospitals.

You will work on a stable healthcare product, contributing to backend architecture and supporting frontend functionality where needed.

Qualifications:

•  5+ years of professional PHP, with real depth in Symfony (DI, console, event handling, Doctrine). We run PHP 8.4 / Symfony 7.4 and stay current.
• Proven external systems integration experience: you have built and operated interfaces for systems you did not control.
• Experience with writing unit and integration tests.
• SOLID, design patterns, and clean architecture.
• Solid MariaDB/MySQL knowledge.
• RESTful APIs.
• Docker and Bash.
• Strong debugging discipline with log correlation.
• Proactiveness: you raise risks, gaps, and bad assumptions early instead of waiting to be assigned the next ticket.
• Ability to decompose an ambiguous requirement into steps that ship independently. Integration work rarely arrives fully specified.
• Clear written and spoken English.

Nice to have:

• HL7 v2, FHIR, DICOM, or hands-on work with an HIS.
• PHPStan and Psalm.
• Fluency with the failure modes of distributed integration: partial delivery, duplicates, ordering, silent schema drift.
• Experience working with JIRA and in an Agile/Scrum environment.
• Regulated-environment experience: medical devices, finance, or comparable.
• Productive use of AI coding assistants (Claude Code, Codex, or similar): you know where they genuinely accelerate work and where their output needs to be treated as a first draft, not a merge candidate.

Your tasks:

• Develop top-notch and maintainable software solutions, implementing modern engineering practices to ensure high product quality
• Engage in technical discussions to identify the best solutions and proactively propose innovative ideas
• Collaborate effectively with team members and management

What you can expect from us:

• Flexible working hours and a healthy work-life balance
• 24 paid vacation days per year + 11 public holidays + paid sick leave
• Fully remote cooperation (Ukraine or any EU country)
• PE accounting support (Cooperation is possible via Ukrainian PE (FOP) only)
• Modern equipment and a powerful laptop
• Flat structure with short decision-making cycles
• Direct collaboration with a German product company

We are currently looking for a Senior AI Platform and Model Operations Engineer to join a professional German-based product company team that designs innovative eHealth solutions for hospitals.

You will work on a stable healthcare product.

You'd own the models and the platform around them, serving every channel we put in front of a patient.

The phone assistant is first because it's already underway, but it isn't the point of the job. Next is a chat assistant in the patient portal that can answer questions and walk someone through booking an

appointment, and after that whatever channel comes along.

The thing you're actually building is one internal API that every channel calls, so that the rules about what a patient can do live in one place instead of being written three times, slightly differently. The phone assistant and the web chat are two front ends onto the same thing.

Alongside that: moving off the vendor. Right now we pay per minute for speech recognition and language models, and within about a year we want to be running them ourselves — because we're dealing with

patient data, and because we don't want a vendor swapping a model underneath us without telling us.

To be clear about scope: we mean serving open-weight models and adapting them to our domain. We don't mean training a model from scratch.

One thing we want to be direct about. We are not looking for someone to build what we've already decided on. We don't yet know whether running these models ourselves is the right call — we don't have an accuracy figure on real German phone audio, and we don't have a proper cost comparison. Your first job is to produce both, and if they say we should keep paying the vendor for another year, we need you to tell us that plainly. Someone who quietly builds the thing because we asked for it is worse than no hire at all. If being the person who says "the numbers don't support this" makes you uncomfortable, this isn't the job.

You need

• To have put a language model behind an API that more than one product called, and kept it running.
• Streaming responses, timeouts, retries, and errors that tell the caller something useful.
• To have run a speech recognition or language model in production on hardware you were responsible for. Not a notebook, not someone else's API.
• To be able to size and cost it: how many people one GPU will serve at once, what an hour of audio or a million tokens costs you, where it starts to fall over.
• Tool calling in production, and a clear view on where the boundary sits. The assistant will guide patients through booking, which means the model proposes an action and our code decides whether it's allowed. If you've built something where the model was effectively trusted to act, we'd want to talk about what you'd do differently.
• To have dealt with untrusted text reaching a model that can trigger actions. A chat box on a patient portal is a much easier thing to attack than a phone call, and someone will try.
• Experience grounding a model on your own content so it stops inventing things — and honesty about where that still fails.
• Experience fine-tuning or adapting an open-weight model, LoRA or PEFT or something equivalent, and the honesty to say whether it was worth the effort.
• A habit of being suspicious of your own benchmark numbers, especially the good ones.
• To understand that using patient conversations to train a model is a different legal question from using them to answer one. If that distinction is new to you, this role probably isn't the right fit.
• Python and Linux, containers, and a serving stack like vLLM or TGI.
• Enough experience to work without an ML team around you, and to tell a team lead something he'd rather not hear.
• We are considering candidates who work through Ukrainian FOP.

Nice to have

• Quantization, and a view on what it costs you in accuracy.
• Audio processing: sample rates, codecs, what a phone network does to a recording.
• GPU scheduling, Kubernetes.
• Having built something where the same assistant had to behave consistently across more than one channel.
• Having worked somewhere GDPR was taken seriously rather than mentioned occasionally.

You don't need

• To have built a voice assistant, or to know anything about telephony. That's the other role, and the phone channel is only one consumer of what you'd build.
• To speak German.
• To know PHP . You'd define what our backend needs to expose; another team builds it.

We are currently looking for a Senior Voice AI Engineer, Evaluation and Reliability to join a professional German-based product company team that designs innovative eHealth solutions for hospitals.

You will work on a stable healthcare product.

Senior level, and we mean it. You would own the evidence that this system is safe to put in front of

patients, on your own judgement, and tell us when the answer is no. That isn't a job we can hand to

someone still learning what to measure.

You would not be building a voice stack. We use a third-party voice platform that already handles the

telephony, the speech recognition and synthesis, and the knobs for end-of-speech detection and

interruption. What it does not do is tell us whether any of that is working well enough for patients, and it

gives us no way to check that a change hasn't made things worse. That's the job.

So you'd own the conversation and the evidence about it: how the assistant behaves when a caller

interrupts, corrects themselves or won't answer; how fast the whole thing responds once a round trip to

our backend is in the loop; and the body of test cases we run before every change.

You need

• To have run a phone or voice assistant that took real calls from real users, and to be able to tell us what its response time was and how you measured it. Having built the audio pipeline yourself is fine but not the point — we care that you know what to measure and what good looks like.
• To have tuned a voice system rather than only shipped one: end-of-speech detection, barge-in, how long to wait before assuming the caller has finished. You'd be doing this against a vendor's settings rather than your own code, and their own documentation says clean barge-in can't be guaranteed on phone audio.
• To know what happens to speech recognition accuracy when the audio comes down a phone line instead of a good microphone, and to have measured it rather than read about it.
• A way of testing conversation changes that doesn't rely on listening to a few calls and hoping. This is the centre of the role. Whatever form it took — a replay harness, a scored scenario set, anything — we want to hear how it worked and where it let you down.
• Enough Python to build that harness and the tooling around it.
• We are considering candidates who work through Ukrainian FOP.

Nice to have

• Having worked against a closed voice platform, with the frustrations that brings, rather than only your own stack.
• Telephony background: SIP , WebRTC, Asterisk, Twilio or similar. Useful for knowing why calls sound the way they do, though you would not be running any of it.
• Work with health data, or any other field where getting it wrong has consequences.
• German, though we're not counting on it.

You don't need

• To speak German.
• To have built streaming audio infrastructure, a turn-taking system or a speech pipeline. The platform does that, and rebuilding it isn't on the table.
• To know PHP or anything about our existing backend. Another team builds the endpoints you'd call.
• To have trained a model from scratch.