An Engineer's Guide to Starting a Side Hustle
From 0 to Your First Paycheck

This won't promise you "NT$100K/month in passive income" ─ that's an Instagram-ad pitch. What it will do is break down 5 types of engineer side hustles, the startup cost and barrier to entry for each, what to do in your first month, and 3 traps 99% of people fall into. Honest, actionable, and not romanticized.

※ This article does not constitute investment, tax, or legal advice. Income from various side hustles may involve moonlighting consent, contracts, invoices, tax filing, and health-insurance adjustments ─ check your own obligations against Taiwan's Labor Standards Act, the Income Tax Act, and your company's employment contract.

First, tear down 3 illusions

01 "Side hustle = passive income"

Wrong.

For the first 6-12 months, a side hustle is active income (you earn what you put in). Passive income requires you to first build an asset (a product / subscription / content library) ─ and that's something 18-36 months down the road.

If "I want passive income" is your motivation, 99% won't last past 3 months.

02 "A side hustle makes money fast"

Also wrong.

The first paycheck from a side hustle usually ─ lands slower than your day job, pays less per hour than your day job, and costs more mentally.

The real value of a side hustle shows up after 6-12 months: you accumulate "skills + credibility + a client network" ─ assets your day job can't give you.

03 "A side hustle will hurt my day job"

This is possible, but usually overstated.

For most people, the 5-8 hours after work are downtime. Reallocating 2 of those hours to a side hustle won't hurt your day-job performance. What actually gets affected isn't time, it's attention (when your side hustle is stuck, you get distracted during the day).

Set one rule ─ never handle side-hustle matters during work hours ─ and you'll avoid most of the side effects.

5 types of engineer side hustle (sorted by barrier to entry)

Which one should you pick? 3 questions to ask yourself

01 How long can you go without income?

• Need money within 3 months → ① Freelancing, ④ Consulting
• Can wait 6-12 months → ② Content, ④ Consulting
• 12 months or more → ③ SaaS, ⑤ Open source

02 Is it money you want in return, or something else?

• Pure money → ① Freelancing is fastest
• A higher hourly rate → ④ Consulting
• Freedom (being your own boss) → ③ SaaS
• Influence → ② Content, ⑤ Open source

03 Are you someone who "can talk to people"?

• Yes → Consulting / content / freelancing, any of them works
• Not really → SaaS / open source (talk to the world through code)

The 5 things to do in your first month

01 Publish what you already have

Don't wait until "it's finished, then I'll publish." Take what you already have ─ GitHub projects, study notes, old articles ─ and pull it together into a personal landing page.

That page is your "credibility savings account" ─ every potential client afterward will click through to take a look.

The technical bar is very low ─ a Notion page / GitHub Pages / a simple HTML site will do.

02 Tell 10 people you're doing a side hustle

For most side hustles, the first client comes from "people who already know you," not cold traffic.

List 10 people you know (former coworkers, schoolmates, friends from tech communities), and DM them: "I'm starting a side hustle doing X-type work ─ if you ever need it, send referrals my way."

Don't underestimate this move ─ I've watched plenty of people land their first side-hustle client exactly this way.

03 Set a concrete goal

Don't set a vague goal like "I want to do a side hustle."

Set:

• "Land my first paying client within 3 months" (freelancing)
• "Hit 1,000 Instagram followers within 6 months" (content)
• "Reach US$100/month in SaaS revenue within 12 months" (SaaS)

The more concrete the goal, the better you can judge "whether I'm drifting off course."

04 Set an "after-hours time slot"

The easiest way for a side hustle to die ─ "work on it when I think of it, stop when I'm tired."

Set a fixed slot, for example ─ Monday, Wednesday, Friday, 8-10pm. Don't touch the side hustle at any other time.

A fixed slot = your expectations and your family's are both set. No fixed slot = the side hustle eats all your time, then turns into burnout.

05 Accept that "your first paycheck is awkward"

A lot of people charge their first client NT$500 and think "that's way too cheap, I might as well not charge."

Wrong.

The value of your first paycheck isn't in the amount, it's in "validating that someone is willing to pay". Once someone has paid, you'll have the confidence to raise your prices and go find the next one.

0 → 1 is 10x harder than 1 → 10.

Pricing strategy ─ 3 principles

01 Your first client can be cheap, but not free

The reason: people value free things to a degree that approaches 0.

Charging a "token" price (like a few hundred New Taiwan dollars) has these benefits:

• The client takes what you deliver seriously
• It's easier for you to quote full price to the next client afterward
• You build the mindset that "I'm worth charging for"

02 Start from "how much they're willing to pay," not "how much I think it's worth"

The way a lot of engineers price ─ their own hourly rate × hours.

This kind of pricing gets stuck at the "time ceiling."

A better question to ask: "If the client doesn't hire me, what does it cost them?"

Example: a client's SaaS keeps crashing after launch, hurting revenue. If they bring me in to review and rescue it, avoiding a week's worth of lost revenue ─ then the value of that review is "a week's revenue," not "my hours × hourly rate."

03 Write it down, don't haggle

Build a simple price list and post it publicly on your personal site.

The benefits:

• It lets unsuitable clients filter themselves out
• It saves you from re-quoting every single time
• It keeps you from getting haggled down live on a call

When a client asks "can you do it cheaper?", your standard answer is: "My price list is public, but if you do X / Y / Z, I can offer A / B / C as add-on value" ─ replace discounts with added value.

3 traps 99% of engineers fall into

01 Starting work without a signed contract

This is the most common blowup in freelancing ─ the client describes the requirements over LINE, you start writing code, and after delivery they say "this isn't what I had in mind, I'm not paying."

The fix ─ before starting work, always get written confirmation (it doesn't have to be a formal contract; an email / LINE message works too):

• What you'll deliver (scope + what's out of scope)
• The delivery deadline
• Payment method / timing (recommended: 30% deposit + 70% on completion)
• A cap on revisions

02 Not budgeting time for "non-development" work

The mistake engineers most easily make when freelancing ─ "I can finish this in 3 days" → it actually took 2 weeks.

Because "3 days" is only the coding time. It didn't account for:

• Clarifying requirements (usually 2-3 back-and-forths)
• Environment setup (every client's environment is different)
• Testing / debugging (always takes longer than expected)
• Delivery / training (the client doesn't know how to use it)
• Payment / receipts / tax filing

When quoting ─ multiply your development hours by 2.5 to get the real time.

03 Forgetting about taxes and health insurance

Once side-hustle income exceeds a certain threshold, you'll have:

• Personal income tax (side-hustle income must be combined into your filing)
• Second-generation NHI supplementary premiums (deducted when a single payment exceeds the threshold)
• Possible changes to your labor-insurance / health-insurance status

This isn't a tax article ─ but I'd recommend you google "side hustle tax filing Taiwan" in your very first month and learn the rules.

Not knowing is fine; once you know, follow the rules ─ don't gamble on getting away with it.

One last reminder

The biggest payoff of a side hustle isn't money.
It's the self-belief that "I've proven I can earn money outside an organization."
That belief changes your relationship with your day job, and with your own career.

Some engineers do a side hustle for 2 years and never end up going full-time ─ but they stop being afraid of layoffs, they dare to push back on their boss, and they dare to turn down unreasonable overtime.

That inner change is worth more than tens of thousands a month.

This article is a map, not a guarantee. A map is only useful to the person who actually walks.