Bug fixes and feature improvements for existing apps by Michal KowalkowskiBug fixes and feature improvements for existing apps by Michal Kowalkowski
Bug fixes and feature improvements for existing appsMichal Kowalkowski
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Please message me on Contra before booking or starting a project. These packages cover example scopes. We will confirm your requirements, scope, timeline and price first, and I can send a tailored proposal. Model/API, hosting and paid-tool costs are separate.
Already have a product, but need someone to make the next change? I can fix a bug, improve a feature, adjust an interface or add a small piece of functionality to your existing app or website. You may have built it yourself with AI, worked with another developer, or inherited a project. I work in the project's existing stack, using AI-assisted development with manual review and testing. Before quoting, I review the code or project access, reproduce the issue or clarify the requested behaviour, and agree on a bounded change. You receive the updated code or project, a tested result and a short explanation of what changed. This can cover different languages and frameworks. Share the stack and the exact change so I can assess the project before accepting the work. Message me with screenshots, steps to reproduce or a feature brief. Larger changes can be split into milestones.
EXAMPLE SCOPES AND PRICES (USD) Small fix — $250 One small, clearly reproducible bug fix or interface adjustment in an accessible project. Indicative delivery: 3 calendar days.
Feature improvement — $625 One bounded feature improvement or small new feature, with checks for the affected flow. Indicative delivery: 5 calendar days.
Related improvements — $1,250 A group of related changes in one area of the product, with regression checks and handover notes. Indicative delivery: 7 calendar days.
HOW I WORK Investigate the existing project Review the relevant code and setup, reproduce the bug or trace the requested feature, and confirm the affected area.
Implement the bounded change Make the agreed fix, interface adjustment or feature improvement in the project's existing stack.
Test and hand over the change Check the affected flow and relevant regressions, then deliver the updated code and a short explanation of the result.
WHAT I NEED TO QUOTE Describe your goal and the exact scope we discussed on Contra. Include the expected result and acceptance criteria. Please provide: Project access or repository, stack and run instructions, screenshots or reproduction steps, expected result, existing deployment process and acceptance criteria.
OUTSIDE SCOPE A full rebuild or an open-ended maintenance commitment. Investigation of an unknown codebase counts as work; quote uncertain fixes after an initial review.
Prices are illustrative for the listed scope, based on actual hands-on time with AI assistance, manual review and testing. We agree on the final scope, price, access and delivery schedule in a custom proposal. Delivery estimates start after complete requirements. One revision round within scope is included.
FAQs

Contact for pricing
Duration1 week
Tags
TypeScript
Software Engineer
Web Developer
Service provided by
Michal Kowalkowski Warsaw, Poland
Bug fixes and feature improvements for existing appsMichal Kowalkowski
Contact for pricing
Duration1 week
Tags
TypeScript
Software Engineer
Web Developer
Cover image for Bug fixes and feature improvements for existing apps
Please message me on Contra before booking or starting a project. These packages cover example scopes. We will confirm your requirements, scope, timeline and price first, and I can send a tailored proposal. Model/API, hosting and paid-tool costs are separate.
Already have a product, but need someone to make the next change? I can fix a bug, improve a feature, adjust an interface or add a small piece of functionality to your existing app or website. You may have built it yourself with AI, worked with another developer, or inherited a project. I work in the project's existing stack, using AI-assisted development with manual review and testing. Before quoting, I review the code or project access, reproduce the issue or clarify the requested behaviour, and agree on a bounded change. You receive the updated code or project, a tested result and a short explanation of what changed. This can cover different languages and frameworks. Share the stack and the exact change so I can assess the project before accepting the work. Message me with screenshots, steps to reproduce or a feature brief. Larger changes can be split into milestones.
EXAMPLE SCOPES AND PRICES (USD) Small fix — $250 One small, clearly reproducible bug fix or interface adjustment in an accessible project. Indicative delivery: 3 calendar days.
Feature improvement — $625 One bounded feature improvement or small new feature, with checks for the affected flow. Indicative delivery: 5 calendar days.
Related improvements — $1,250 A group of related changes in one area of the product, with regression checks and handover notes. Indicative delivery: 7 calendar days.
HOW I WORK Investigate the existing project Review the relevant code and setup, reproduce the bug or trace the requested feature, and confirm the affected area.
Implement the bounded change Make the agreed fix, interface adjustment or feature improvement in the project's existing stack.
Test and hand over the change Check the affected flow and relevant regressions, then deliver the updated code and a short explanation of the result.
WHAT I NEED TO QUOTE Describe your goal and the exact scope we discussed on Contra. Include the expected result and acceptance criteria. Please provide: Project access or repository, stack and run instructions, screenshots or reproduction steps, expected result, existing deployment process and acceptance criteria.
OUTSIDE SCOPE A full rebuild or an open-ended maintenance commitment. Investigation of an unknown codebase counts as work; quote uncertain fixes after an initial review.
Prices are illustrative for the listed scope, based on actual hands-on time with AI assistance, manual review and testing. We agree on the final scope, price, access and delivery schedule in a custom proposal. Delivery estimates start after complete requirements. One revision round within scope is included.
FAQs

Contact for pricing