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Expert Advisors
Your rules, written as code that does exactly what the specification says, and nothing it does not. Every input documented and configurable.
Home / MQL5 & EA development
MQL5 development and Expert Advisor testing
You have a strategy. You need it built properly, tested honestly, and running without falling over. That is the job. I write the code and build the testing around it — the strategy, and every decision about trading it, stays entirely yours.
Fig. 01Scope
What I do, and what I do not
Worth stating plainly up front, because it saves us both a call.
What I do
- Code Expert Advisors, indicators and scripts to your written specification
- Convert an existing strategy, rule set or MQL4 code into working MQL5
- Build the backtesting and optimisation setup so you can evaluate it yourself
- Implement your risk controls — position sizing, exposure limits, stop logic
- Add logging, alerting and safe-failure behaviour for unattended running
- Fix, refactor and document EAs somebody else wrote
- Set up VPS deployment and monitoring
What I do not
- Advise on whether a strategy is any good, or suggest one
- Provide signals, tips or market opinions
- Make any claim about performance, profitability or returns
- Sell or licence a ready-made "winning" EA
- Manage accounts, handle client money, or trade on anyone's behalf
- Guarantee an outcome from any piece of software
Fig. 02The work
What gets built
The difference between an EA that survives contact with a live market and one that does not is rarely the entry logic. It is everything around it.
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Indicators and scripts
Custom indicators, panels and utility scripts, built to run efficiently rather than eating the terminal.
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Testing and optimisation setup
Strategy Tester configured properly, with the parameter ranges, data handling and walk-forward structure set up so the results you get out mean something.
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Risk and safety logic
Position sizing, exposure caps, spread and slippage filters, trading windows, and the checks that stop it acting on bad or missing data.
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Unattended operation
Logging, alerting, reconnection handling, and defined behaviour when something is wrong. It should stop safely rather than carry on and make it worse.
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Rescue and refactor
Inherited an EA nobody understands? I will read it, document what it genuinely does, and either repair it or tell you it needs rewriting.
Fig. 03Method
How I work
Same method as everything else I build. The specification stage matters more here than anywhere, because an ambiguous trading rule becomes an expensive bug.
01Pin down the rules
We go through your strategy line by line until every rule is unambiguous. What counts as a signal. What happens on a gap, a requote, a partial fill, a disconnection mid-position. Most of the value is here — this is where the questions nobody thought of get asked.
Output A written rule set with the edge cases resolved.
02Specify
Inputs, defaults, risk controls, logging, failure behaviour and the tests it has to pass. The fixed price comes out of this document, and so does the definition of finished.
Output A written scope with acceptance criteria, approved by you.
03Build
Written to the spec, commented, with the risk and logging layers in from the start. You get progress as it goes, not a reveal at the end.
Output Compiled EA plus source, running in the Strategy Tester.
04Verify
Tested against every acceptance criterion, with deliberate attention to the awkward cases: missing bars, weekend gaps, broker rejections, restart mid-position. I am checking that it behaves as specified, not that it makes money — that part is yours to evaluate.
Output Written test results against each criterion, and your sign-off.
05Hand over
Source code, a documented input reference, notes on what it does and does not handle, and a walkthrough. If you want it on a VPS, I will set that up and show you the monitoring.
Output Source, documentation, walkthrough and a 30-day check-in.
Fig. 04Engagement
What it costs
Fixed price against a written specification. Complexity drives the number, so the rule-pinning stage comes first and the quote comes after it.
Typical engagements
Fixed-price builds
Quoted once the rules are written down and unambiguous, not before.
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Indicator or script
Single-purpose, self-contained From £180 -
Expert Advisor
Single strategy, single instrument, coded to your specification From £550 -
Expert Advisor — advanced
Multi-instrument, advanced risk handling, state that survives a restart £1,200 – £2,200 -
EA diagnostic
Your code read and run, with a written report on what is broken and what it will cost to put right. Credited in full against the work if you proceed £95 -
Review, debug and harden
Your existing EA tested against its failure modes and documented. Quoted from the diagnostic Starting fee £250 -
MT4 to MT5 migration
Ported, tested and documented. Quoted against the MQL4 source, because a clean single-strategy build and a decade of accumulated patches are not the same job From £400 -
Optional support
Changes and help after handover On request
I do not take build work under £180, and I do not reproduce a system from a screenshot or a results page with no specification and no source. If that is what you need, I am the wrong person, and I would rather say so before you spend anything.
Discuss a buildBefore anything is quoted
The rule-pinning stage
Most quotes go wrong because the strategy was described in a paragraph and turned out to need forty decisions. So that happens first, in writing, and the price follows from it.
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Rules workshop
Working through your strategy in detail Included -
Written specification
Edge cases resolved, tests defined Included -
Then a fixed quote
Which you are free to walk away from No obligation
You get the source code
The Expert Advisor built to your strategy is yours. Full MQL5 source, commented, delivered with the specification it was written from. Take it to another developer tomorrow if you want to. What stays mine are the generic building blocks underneath — the order-handling, error-recovery and state libraries reused across every build — which you hold a permanent right to run as part of your system.
Your strategy stays private
Confidentiality is written into my standard terms, both ways, from the first conversation. If you would prefer a separate non-disclosure agreement in place before you send anything, I have one ready to sign, at no cost. No strategy I am shown is discussed, reused, or traded on.
You will hear back
The markets do not keep office hours, and neither does an enquiry. You will have a reply within one calendar day.
Fig. 05Questions
Common questions
Will the EA you build make money?
I have no idea, and anyone who tells you otherwise is selling you something. I am responsible for the software doing exactly what your specification says, reliably and safely. Whether the strategy behind it is sound, and whether to trade it at all, is your judgement and your risk. I do not give advice on either.
Do I have to share my strategy with you?
Yes, in enough detail to code it — there is no way round that. It is covered by a mutual non-disclosure agreement signed before you send me anything. I do not trade client strategies, resell them, or reuse them in anyone else's build. The generic engineering underneath — risk handling, logging, testing structure — is reusable and stays mine, which is what keeps the price where it is.
Who owns the code?
Your strategy and the specific implementation of your rules are yours. You get the source, plus a perpetual licence to run and modify it. I keep ownership of the generic reusable components — the risk module, the logging framework, the testing harness — because those are not specific to you. If you want outright ownership of everything, that is available and priced separately, agreed in the scope before I start.
Can you optimise my EA to get better backtest results?
I can set up the optimisation properly and show you how to run it. I would also caution that a backtest tuned until it looks good is generally a curve fitted to the past. Building the testing so it is honest — out-of-sample periods, walk-forward, realistic spread and slippage — is more useful than making the equity curve steeper, and it is what I would rather be paid for.
Will you run it on a live account for me?
No. I will set up a VPS, deploy the software and show you the monitoring, but the account is yours and stays under your control. I do not manage accounts, hold client funds or place trades on anyone's behalf. That is regulated activity and it is not what this is.
Important
BrightDragon Systems Ltd provides software development services only. Nothing on this page is investment advice, a recommendation, or an invitation to trade. I am not authorised or regulated by the Financial Conduct Authority and I do not provide regulated financial services.
Trading carries risk and you can lose money. Any decision to trade, and any strategy the software implements, is entirely yours. No software can guarantee an outcome, and past testing results are not a reliable indicator of future results.