Senior Full-Stack Developer for Confidential Web Project

SENIOR SOFTWARE ARCHITECT /
FULL-STACK DEVELOPER WANTED
Confidential Dual-Platform Web Project · Freelancer.com
ENGLISH
Project
We are looking for a highly experienced Software Architect / Senior Full-Stack Developer for the
professional implementation of a demanding web project consisting of two independent platforms.
The concrete product concept, names and commercially sensitive business logic are
deliberately not disclosed publicly. Qualified candidates will receive the relevant
specification under an appropriate confidentiality agreement.
Single developer wanted – no artificially inflated team structure. The assignment is deliberately
designed around one competent, experienced developer. AI-assisted development is explicitly
encouraged and should be used intelligently to improve efficiency.
Builder Engine: A suitable Builder Engine already exists. The client/founder will bindingly
specify which existing variant is to be used. The developer is not expected to build a new
Builder Engine or independently select an alternative. The selected variant is intended to
be reused across the designated areas of both platforms.
Two platforms / shared technical approach
Apart from design, frontend expression and genuinely platform-specific requirements, the two platforms
should be technically as identical as reasonably possible. Shared CORE components and the selected
Builder Engine variant should be reused wherever appropriate.
The goal is not to develop the same technical system twice. Shared components should be built cleanly
for reuse, while genuine platform-specific differences remain clearly separated.
High client expectations / active collaboration
The client/founder has high expectations regarding quality, attention to detail, technical
cleanliness and traceability. At the same time, there is no expectation of artificial 100%
perfection; software does not reach absolute perfection. The expectation is a clean, robust
and appropriately mature solution across all relevant areas for the current development
stage.
The client will actively participate: he will be directly available as the primary point of contact,
continuously follow development on the provided subdomains, conduct reviews, answer questions,
make required decisions and provide timely feedback. This collaboration is an explicit part of the project
and must be included in the schedule.
This is not a 'hand over the brief and disappear for months' project. The client wants to see progress
continuously and work with the developer step by step toward a robust result.
Frontend, screenshots and attention to detail
Concrete frontend/design specifications and screenshots for user areas and accounts are
already available. These are the working basis. Details shown in them are expected to be
implemented not merely visually, but functionally, cleanly and with strong attention to
detail.
Small details visible in the provided screenshots and specifications are expected to be taken seriously:
spacing, states, interactions, forms, error handling, navigation, responsive behaviour and actual
functionality must work together coherently.
CONFIDENTIAL — Developer Recruitment Page 5
Beta target / testable result
The project must result in a clean, objectively testable, documented and acceptance-ready
beta level, not merely a technical prototype. Test users in the intended roles, providers
and bidders/users, must be able to use and test the essential intended workflows.
Necessary external service providers will initially be prepared through clean adapter/interface
boundaries. Live integrations with necessary external providers are generally connected only after
project acceptance and after a decision that the result is suitable for the beta phase. Core business
logic should therefore not be unnecessarily tied to a specific provider.
Acceptance means traceable acceptance criteria, reproducible build, documented tests, known
remaining issues and a clear statement of the actual achieved status.
Milestone, progress and payment model
Before implementation starts, a binding milestone and delivery schedule is required. The developer
should define work packages, expected outputs and acceptance criteria.
The client wants to verify real progress at least every 14 days through demonstrable
results. A preferred payment model is therefore an initial deposit followed by payments on
a 14-day cycle, each linked to demonstrable progress. Alternatively, clearly defined
milestone payments may be agreed.
The work must be organized so that there is something genuinely demonstrable after each 14-day
period. The provided subdomains serve as continuously accessible development/test environments.
The original schedule must already include sufficient contingency for detail discussions, questions,
adaptations, corrections, reviews, integration issues and normal rework within the agreed specification.
These should not repeatedly become unexpected additional-cost negotiations.
# Area Expected result
1 Technical review &
implementation plan
Specification review, architecture, backlog, acceptance criteria, schedule
2 Foundation / database / CORE Project foundation, DB, migrations, core architecture, test/build basis
3 Identity / accounts /
authentication
User accounts, authentication, sessions, security, roles/permissions
4 Core domain / platform logic Domain workflows, state handling, policies, audit, concurrency
5 Commercial / transaction logic Pricing/fees, payment abstraction, ledger/settlement where specified
6 Media / location / search /
communication
Media, location, search, messaging/notifications as specified
7 Builder / API / infrastructure Client-selected existing Builder Engine variant, API, infrastructure
8 Frontend / design / platform UX Provided design specifications, account screens, detailed frontend
implementation
9 Full QA / correction / integration E2E, security, performance, correction loops and acceptance preparation
10 Beta acceptance Both platforms at test-user-ready beta level; documentation and handover
Schedule: For one highly experienced developer, a realistic target range of approximately
5–7 months to beta acceptance is used, subject to the final technical gap analysis. AI
assistance is explicitly encouraged and may be included in productivity planning.
The schedule must already contain contingency. Artificially short promises are not wanted; neither is
unnecessary project extension through an inflated staffing structure.
Important: The 5–7 month range is a planning framework, not a blank cheque for unlimited scope
expansion. The agreed specification and accepted beta scope remain decisive.
CONFIDENTIAL — Developer Recruitment Page 6
Development environment
Webspace, subdomains and the intended development/test environments are provided by
the client. Development is expected to take place on those environments. Credentials will
be exchanged separately and never posted publicly on Freelancer.com.
Working style expected
• Very high quality standards and proven experience with complex web platforms.
• Clean, testable implementation rather than a quick demo.
• Respect the binding specification; clarify open technical points transparently.
• Use AI intelligently while taking full technical responsibility for the result.
• Provide regular demonstrable progress.
• Take direct client feedback constructively and implement agreed corrections promptly.
• Traceable commits, tests, documentation and reproducible builds.
• Avoid unnecessary reinvention where requirements or existing components already define the solution.
Please include in your proposal
• comparable complex projects and your actual role
• seniority and technical strengths
• experience with AI-assisted development
• realistic 5–7 month plan
• hourly rate and/or preferred payment model
• available hours per week
• portfolio / GitHub / references