Improve an existing product.
Fix bugs, reduce loading times, make code easier to maintain and add the features you need.
Vladyslav Khyrsa.
AI-assisted portraitFull-stack development · From idea to product
FULL-STACK DEVELOPMENT / FROM IDEA TO PRODUCT
From ideato product.
I’m Vladyslav, a full-stack engineer with seven years of experience. I turn ideas into web and mobile applications, from defining requirements to development and launch. I also improve and maintain existing products.
7 yearsProfessional experience
Idea → ProductWeb & mobile delivery
01 / PERSONAL RESPONSIBILITY
You workdirectly with me.
I take your application from requirements to launch.
I define requirements, design the architecture, build the backend, APIs and user interfaces, and set up testing, CI/CD, hosting and monitoring. Backend engineering is my strongest specialism, with a focus on databases, performance and reliability.
You speak with the person doing the work. I keep you informed about progress, decisions and anything that affects the plan.
UNDERSTANDIMPLEMENTVERIFY
See how I can help02 / WHERE I CAN HELPEXISTING PRODUCTS AND NEW APPLICATIONS
Improve what exists.Build what’s next.
I fix problems in your existing software and build the features your business needs.
Build a business application.
Plan and build a website or mobile app that supports the way your business works.
A CLEAR STARTING POINT
Find out what is slow.
Check the pages and requests that are taking too long, then find where the delay starts.
WHAT YOU RECEIVE
Explore the processMeasurements of current performance, the changes I recommend and how we’ll check the result.
COMPLETE PRODUCT DELIVERYWEB + MOBILE
From your idea
to a working product.
I help define your requirements, design the application architecture, build the backend and user interfaces, and set up testing, CI/CD and hosting. You receive a working product, source code and documentation.
- 01
Plan
Clarify your goals, who will use the product and what it needs to do.
- 02
Design
Plan the application architecture, data and user flows.
- 03
Build
Develop the backend, APIs and web or mobile interface.
- 04
Test
Check features, access permissions and performance.
- 05
Launch
Set up CI/CD, hosting, domains and production monitoring.
- 06
Hand over
Provide the source code, documentation and instructions for running the product.
THE RESULT
Discuss your productYour website or app, running and ready to use.
THE PRINCIPLE BEHIND THE WORK
Untangle it.Find the flow.
I look at how the parts connect, find what is causing problems and work out what needs to change.
03 / PRODUCT IMPROVEMENTANALYSE → IMPROVE → VERIFY
Faster pages.More reliable software.
I improve slow or unreliable software, make code easier to maintain and automate repetitive tasks.
01 / PERFORMANCE ENGINEERING
Find the bottleneck.
Improve the flow.
I find what is slowing the application down, improve the code or database queries, then measure the result.
UP TO50×
Faster responses for
specific backend requests
specific backend requests
Achieved through optimisation, without increasing server capacity.
PAGE-LOAD IMPROVEMENT
BEFORE60–90s
AFTER3–5s
Approximate load times for typical pages during peak usage.
A separate result from the backend response improvement.
REQUEST→Optimised execution→RESPONSE
Illustration of request processing
How I do this
- WHAT I INVESTIGATE
- Pages, server responses and database queries that take too long. I identify where delays occur.
- HOW I WORK
- I use logs, request tracing and database tools to find the cause. I improve the code or data access, then measure the same requests again.
- WHAT I DELIVER
- Implemented improvements, before-and-after timings and an explanation of the results. Previous work includes up to 50× faster responses for specific backend requests. Typical page loads during peak usage fell from approximately 60–90 seconds to 3–5 seconds; this is a separate result.
02 / LONG-TERM RELIABILITY
Stability that
supports growth.
Detect→Resolve
Find out why errors keep happening, fix the cause and set up alerts for problems.
How I do this
- WHAT I INVESTIGATE
- Errors that keep happening, interrupted work and servers running out of resources. I check what was happening when each failure occurred.
- HOW I WORK
- I investigate the cause, implement fixes, improve error handling and set up monitoring and alerts. I also test how the application behaves when an external service fails.
- WHAT I DELIVER
- Fixes for the causes I find, error handling and alerts that help you spot problems sooner.
03 / CODE MODERNISATION
Code that’s easier
to maintain and extend.
Untangle→Simplify
Refactor existing code to make it easier to understand, maintain and extend.
How I do this
- WHAT I INVESTIGATE
- Code that is difficult to understand, maintain or extend. I review its structure and dependencies.
- HOW I WORK
- I separate code by responsibility, remove unnecessary duplication and refactor the parts that need improvement. I test that existing features still work.
- WHAT I DELIVER
- Code that is easier to understand, maintain and extend, with documentation explaining its structure.
04 / BUSINESS AI INTEGRATION
AI that works
within your product.
Add an assistant that can use your application’s data and tools, with rules about what it can see and do.
How I do this
- WHAT I INVESTIGATE
- What the assistant should do, which data it needs and who should have access.
- HOW I WORK
- I connect the data and tools, set access rules and test the results. I check how the assistant handles unclear questions, errors and requests it should refuse.
- WHAT I DELIVER
- An assistant that works with your application’s data and tools, with access rules and tests for the tasks it is allowed to perform.
AI INTEGRATIONTHE APPROACH
Start with a clear business task.
Define. Connect. Validate.
Decide what the assistant should do, connect the data it needs and test its answers and actions.
TASKRULESACTION
Decide what it can do. Check that it works.
05 / USER ACTIVITY & ACCESS HISTORY
Make important
actions visible.
See who changed what, when it happened and how access permissions changed.
How I do this
- WHAT I INVESTIGATE
- Which actions and permission changes your team needs to see, and who should be able to view them.
- HOW I WORK
- I record the actions that matter, add search and filters, and control who can see the records.
- WHAT I DELIVER
- Searchable audit records of relevant user actions and permission changes, so your team can see who did what and when.
06 / ANALYTICS & REPORTING
Less repetitive work.
More useful information.
Generate reports automatically and put the information your team needs in one place.
How I do this
- WHAT I INVESTIGATE
- Reports that require repeated manual work or data from several places.
- HOW I WORK
- I organise the data, check the calculations and automate repetitive steps. I build reports that answer your team’s business questions.
- WHAT I DELIVER
- Reports and analytics within your application, with less manual data collection and preparation.
04 / HOW WE WORK
How we’llwork together.
We agree on the work before development starts. You know what I’m doing and how we’ll check it.
01
Investigate
Understand the problem and what you need to change.
Understand the problem.
We talk about the problem and what you want to change. I review the code, data and parts of the application involved.
YOU RECEIVE
A summary of the problem and the changes I recommend.
Agree on the work.
We agree on what to build, what it will cost and what needs to happen first. If the work changes, we discuss it before I continue.
YOU RECEIVE
An agreed plan, estimate and list of tasks.
Build and test the changes.
I build and test the changes, check the result against what we agreed, and prepare the code and documentation for you.
YOU RECEIVE
The finished work, test results and instructions for running it.
05 / TECHNICAL SKILLSLANGUAGES, FRAMEWORKS & SERVICES
The tools
I work with.
The technologies I use to build, improve and maintain your product.
Languages & runtime
TypeScript · JavaScript · Node.js · Worker threads · Clustering
Backend & APIs
NestJS · Express · REST APIs · GraphQL · WebSockets / Socket.IO
Databases & data access
PostgreSQL · MongoDB · Redis · Prisma · TypeORM
Web & mobile
React · Next.js · React Native · Expo
Hosting & compute
Vultr · AWS EC2 · AWS Lambda · Elastic Beanstalk
AWS storage & services
S3 · Elastic Container Registry (ECR) · EventBridge
Version control & delivery
Git · GitHub Actions · Docker · CI/CD · Production deployments
Domains & routing
Domain registration · DNS configuration · Routing · HTTPS setup
Monitoring & debugging
CloudWatch · OpenTelemetry · Jaeger · Sentry · Operational alerts
Testing & API security
Jest · Supertest · Cypress · Access control · Rate limiting · Application-level intrusion detection and prevention (IDS/IPS)
ALSO IN WRITING
Read on Medium Technical articles on Node.js and backend development.
06 / BEFORE WE TALK
A few useful
answers.
Can you build a product from scratch?
Yes. I work with you to turn the idea into requirements, design the architecture, build the backend, APIs and web or mobile interface, and set up testing, CI/CD and hosting. You receive a working application, source code and documentation.
Can you take over an existing application?
Yes. I review the existing code, fix problems and continue development. We agree on the priorities before I make changes.
What does the first conversation cover?
Tell me what you want to build or improve, who it is for and what you want to achieve. A short description helps us decide where to start.
How do you estimate the work and price?
I estimate the work after reviewing your requirements. We agree on what is included and the price before development starts. If requirements change, we discuss the effect on cost and timing.
Do you integrate AI into existing products?
Yes. I connect AI assistants to your application’s data and tools. I set access rules and test how they handle unclear requests, errors and tasks they should not perform.
How do you approach quality?
I test the changes and check the result against what we agreed. For performance work, I compare timings before and after. I explain what was checked and provide instructions for running and maintaining the product.
OPEN TO NEW PROJECTS & DIRECT CLIENT COLLABORATION
Tell me aboutyour project.
Send me a short description of what you need.
Tell me what you want to build or improve and why. I’ll reply so we can discuss the work.
[email protected]