Chapter 259: Sandbox and Scale

Beside the self-service kiosk in the first-floor lobby, a row of blue plastic chairs sat waiting for families. The chair backs were worn smooth and shiny, with fine cracks along the edges. Lin Chen chose the spot closest to the wall, where the power outlet was intact. He set his canvas bag at his feet, its zipper half-open. He pulled out his laptop, plugged it into the power, and connected the Ethernet cable. The screen lit up, and a terminal window popped up. The process list for the sandbox environment was neatly arranged, like a row of soldiers awaiting inspection. He typed the final validation command and hit Enter. The progress bar advanced slowly, the percentage digits ticking upward one by one.

The bandage around his left ankle had loosened slightly, the ointment seeping out and drying into a pale yellow crust at the edges. He reached down to rewrap it tightly, his movements practiced and uninterrupted. The ibuprofen was wearing off, the pain shifting from a dull ache to a fine, needle-like prickling that crept up his calf muscles. He adjusted his posture, shifting his weight entirely to his right side, leaving his left leg slightly suspended with just his toes lightly touching the floor. 9:15 AM. The meeting link popped up on schedule. He put on his headphones and clicked to join.

Three windows appeared on the screen. Su Man’s avatar was in the top left corner, against a backdrop of gray-white office partitions; stacks of stress-test reports were visible on her desk. Zhao Qiming’s window was centered, the lighting slightly dim, revealing neatly arranged industry yearbooks and a few well-worn financial manuals on the bookshelf behind him. No pleasantries. Lin Chen shared his screen and switched to the console.

“Data source connected. Raw sample size: thirty-two thousand records, containing non-standard characters, line breaks, and duplicate fields. Cleaning pipeline initiated.” He pressed Enter.

The log window began to scroll. Green INFO and yellow WARN tags alternated, resembling waveforms on a cardiac monitor. The latency curve on the right-hand chart climbed slowly, its peak kept within eighty milliseconds. Su Man’s voice came through the audio, low and steady: “Full-link nodes normal. Memory usage at forty-two percent. CPU has not hit its ceiling.”

Zhao Qiming said nothing, his eyes fixed on the throughput metrics on the screen. His fingers tapped lightly on the desk, the rhythm steady.

Lin Chen continued: “Triggering anomaly injection. Simulating upstream interface timeout.”

The curve jittered briefly, then quickly stabilized. The system automatically switched to the backup queue with no data loss. A line popped up in the logs: Fallback activated. Queue drained.

“Fault tolerance mechanism is active.” Lin Chen’s voice was even, his pace controlled at around one hundred twenty words per minute. He didn’t need to embellish; the data would speak for itself.

Zhao Qiming finally spoke: “What’s the post-cleaning structuring rate? And the false positive rate for edge cases?”

Lin Chen pulled up another chart. “The current version’s structuring rate is ninety-four point seven percent. False positives are concentrated mainly on rare place names and mixed legacy encodings. The false positive rate is one point two percent, already covered by a manual review fallback. If we need to push it down to five per thousand, we’ll need to increase the pre-training samples for the rule engine, which will raise costs by fifteen percent.” He paused for half a second, then added: “This is a technical boundary, not a flaw.”

“Team configuration? Delivery timeline?” Zhao Qiming asked.

“Two core developers, one QA. I’ll handle architecture and the core pipeline; Su Man will handle stress testing and deployment. First version delivery requires fourteen days, including three iteration cycles.”

A sudden spasm shot through his left leg. Without changing his expression, he pressed his toes to the floor to leverage the tension and ease it. Cold sweat beaded at his temples; he wiped it away with a light touch. Only a faint static hum remained in his headphones.

“What if requirements change midway?” Zhao Qiming asked.

“We’ll re-evaluate the hours based on the changed modules. Anything outside the original scope will be billed separately. It’ll be specified in the contract.” Lin Chen replied. He didn’t dodge the question, nor did he promise the impossible. He knew Zhao Qiming wasn’t looking for a polished PowerPoint; he wanted quantifiable risk boundaries.

Zhao Qiming fell silent for a few seconds. The light on the screen seemed to dim slightly as he adjusted his posture. “Alright. Send over the architecture diagram, cost breakdown, and delivery milestones. We’ll run it through our internal process. You’ll have an answer by Wednesday.”

“Understood.” Lin Chen stopped screen sharing. The meeting ended.

Only a faint static hum remained in his headphones. He took them off and rubbed his stiff neck. The log window on the screen had stopped scrolling; the final line read Pipeline completed. 0 errors. He saved the logs, closed the terminal, shut the laptop, and unplugged the Ethernet cable.

As he stood up, his left leg went numb. He gripped the back of the chair, waited two seconds, and steadied himself. He slung the canvas bag back over his shoulder and zipped it up. He walked toward the elevator, heading back to the ward.

His phone vibrated in his pocket. It wasn’t Su Man, nor was it Zhao Qiming’s assistant. It was a text from the hospital system: Patient Lin Xing (epilepsy) medication reminder: Sodium valproate extended-release tablets are running low in stock. It is recommended to visit the outpatient pharmacy today to confirm alternative options or secure a supply in advance.

Lin Chen stopped. The elevator doors slid open in front of him, revealing an empty car. He stepped inside and pressed the floor button. The metal doors closed slowly. In the mirrored reflection, his complexion was somewhat pale, the dark circles under his eyes deeper than yesterday, but his gaze remained calm.

He pulled out his hardcover notebook and flipped to a fresh page. The edges of the paper were already curled, but the scale lines inside were perfectly aligned, not a single one out of place. His pen touched down, and he wrote two lines:

1. Sodium valproate alternative (requires blood concentration verification; pharmacy quote pending). 2. Zhao’s reply window: 72 hours. Financial baseline remains fixed.

The elevator ascended. A slight sensation of weightlessness washed over him. He leaned against the cabin wall and closed his eyes. The demo was over, but the accounts weren’t balanced yet. The technology could run smoothly, but the variables in reality kept multiplying. He needed to go to the pharmacy, confirm the drug prices, and calculate how long the thirty-thousand reserve would last if Zhao Qiming tried to squeeze the price. Xiao Man’s EEG follow-up was scheduled for next Friday; the examination fee plus medication would cost at least four thousand. If Zhao Qiming’s project went through, the final payment would cover it; if not, he’d have to take on more freelance work, or extract the cleaning module from the sandbox and sell it to small data annotation firms.

There was no way back, only options.

The elevator chimed. The doors opened. From the corridor came the sound of a nurse’s cart wheels, the rubber tires rubbing against the terrazzo floor, producing a steady, rustling rhythm. The smell of disinfectant was fainter than in the morning, but still distinct.

Lin Chen stepped out, right foot first, left following. His pace was still unhurried, but his direction was clear. He touched the hardcover notebook in his pocket, the rough texture of the paper transmitting through the fabric to his fingertips.

The next step was the pharmacy. And the starting point of the next round of calculations.